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 Barlow ; Rev. Professor Jeuemie ; W. Lowndes, Esq., M. A., Q.C. ; 
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 ADVERTISEMENT. 
 
 ENCYCLOPiGDIA METROPOLITANA. 
 
 Second Edition, Revised, 
 
 ORDER OF PUBLICATION. 
 
 Z. IVfiEXZiT PABTS. 
 
 PART 
 
 1. METHOD. By S. T. Coleridge 
 
 2. UNIVERSAL GRAMMAR. By Sir John Stoddart. Part I. 
 
 3. LOGIC. By Archbishop Whately. Part I. . . . 
 
 4. LOGIC, By Archbishop Whately. Part IL (conclusion) . 
 
 5. RHETORIC. By Archbishop Whately. Part I. 
 
 6. RHETORIC. By Archbishop Whately, Part II. (conclusioiC) 
 
 7. HISTORY OF EARLY CHRISTIANITY. Bv Bishop Hikds. 
 
 Part I * 
 
 8. HISTORY OF THE jews! By Archdeacon Hale. Part L 
 UNIVERSAL GRAMMAR. By Sir John Stoddart. Part II 
 HISTORY OF EARLY CHRISTIANITY. By Bishop Hinds. 
 
 Part II. 
 
 HISTORY OF THE JEWS. By Archdeacon Hale, Part II 
 
 MORAL AND METAPHYSICAL PHILOSOPHY. Bv the 
 
 Rev. Professor Maurice. Part I ' . 
 
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 1. METHOD By S. T. Coleridge 
 
 2. UNIVERSAL GRAMMAR. By Sir John Stoddart '. 
 
 3. LOGIC. By Archbishop Whately 
 
 4. RHETORIC. By Archbishop Whately . . * 
 
 I' Hi^r'^S^^ ^^ ^^^LY CHRISTIANITY. By Bishop Hinds. 
 ^- £^y^^^^^ ECONOMY. By Nassau W. Senior, Esq. . 
 7. MORAL AND METAPHYSICAL PHILOSOPHY. By the 
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PKOSPECTUS. 
 
 1. An Encyclopedia is indispensable to every library, as a concentration of human 
 knowledge ; while to the voyager, the naval and military officer, the colonist, and 
 that numerous class of enterprising Britons whose want of a settled residence may 
 isolate them from the world of letters, it is the only possible substitute for all other 
 books. Works of this description are therefore among those few literary pi'ojects 
 which have uniformly secured the patronage of the public. The reason is obvious : 
 an Encyclopaedia, is to the rising education of the country at once a reservoir and a 
 fountain—it receives perpetual accessions of knowledge from the genius of the age, 
 ■which it yields again in willing abundance to posterity. 
 
 2. With the ancients, the term Encyclopaedia, explained itself. It was really In- 
 struction in a cycle, i. e. the cycle of the seven liberal Arts and Sciences, that consti- 
 tuted the course of education for the higher class of citizens. Unfortunately, the 
 inapplicability of a strictly scientific method to a modern Encyclopaedia, such as 
 shall include the whole of its contents, has led to the abandonment of all principle of 
 rational arrangement ; and it may be safely asserted of all our universal dictionaries 
 hitherto, that the chief difference between them, in respect of their plan, consists in 
 the more or less complete disorganization of the Sciences and Systematic Arts ; 
 now retaining certain integral portions of the system as integers, forming each an 
 entire treatise, but resigning these treatises to the places severally assigned to them 
 by the accident of their initial letters ; and now splintering all alike into their 
 fractional parts, with an arrangement merely alphabetical. Nor has the imper- 
 fection rested here. This very alphabetical position was but too frequently deter- 
 mined by the caprice or convenience of the compiler ; inasmuch as the division of 
 parts into minor parts had no settled limit. Thus, one technical or scientific term 
 included as its subordinates, and to be explained in the same article, sometimes 
 more, sometimes fewer, other terms : and the arrangement became neither properly 
 scientific, nor properly alphabetical. It had the inconveniences of both, without the 
 advantages of either. 
 
 3. The results are such as might have been expected, in part from the necessity 
 of such plans, and in part from the interference of individual whim, carelessness, 
 and procrastination, to which it afibrded the amplest opportunities, and even fre- 
 quent temptation. Numerous articles of important information are found where 
 the reader could have least expected to find them ; while articles of equal interest 
 are in many cases not to be found at all. 
 
 4.^ A second result is, that an Universal Dictionary so constructed, equally with 
 an Encyclopaedia the most methodically arranged, requires alphabetical references; 
 but with a twofold inconvenience, from which the latter would be free. First, the 
 references, instead of being collected in one appropriate index, or at least in some 
 known portion of the work, are scattered throughout the whole ; and this is no 
 slight annoyance, when a scientific term happens to have many synonyms, as, for 
 instance. Azote, Nitrogen, Phlogisticated Air, &c. Secondly, the references must 
 eventually lead the reader through as many volumes, as those other words happen 
 to be placed in, which are necessary to be jneviouslt/ understood in order to a tole- 
 rable comprehension of the term first sought. 
 
 5. A third evil, resulting from the same causes, is the utter want of all proportion 
 in the space occupied by each article, relatively either to the importance of the 
 particular subject, or to the promised limits of the whole work. Hence, too, it 
 arises that the proprietors are frequently reduced to a choice of evils. The work 
 must be extended far beyond the first expectation of the purchasers, or the articles 
 assigned to the latter volumes must be crowded in scanty and superficial abridg- 
 
SCHEME OF THE ORIGINAL EDITION. 3 
 
 raents. They contract to give the public an Universal Dictionary of the Arts and 
 Sciences, but the execution outgrows the plan. Eitlier openly then, or in the form 
 of supplementary volumes (bearing perhaps a large proportion to the whole work), 
 this pledge must be redeemed. In both cases the disorder and dislocation, and in 
 many instances the deficiencies, remain unremedied. 
 
 6. The fourth ill consequence of this arbitrary arrangement calls for a somewhat 
 fuller consideration. It requires but a moment's reflection to be convinced, that tlie 
 most voluminous Encyclopgedia which has yet appeared, is incomparably too narrow 
 to contain an Universal History of Knowledge in its present state ; and that the 
 authors and compilers will have satisfied all rational expectations if only nothing 
 shall be found excluded from any other cause than the higher importance of that 
 which has been admitted ; in order that on all subjects the ends of general infor- 
 mation at least may be accomplished. Where, therefore, selection is so imperiously 
 required, there must be an equal necessity that certain fixed and intelligible prin- 
 ciples should be pre-established. An Encyclopscdia neither is, nor can reasonably 
 be considered as, the book which a man of profound science is likely to consult for 
 those things in which he is himself eminent. He will seek for accessions to his 
 knowledge in the works of contemporaries employed like himself in extending the 
 poraoeria of science, and will often be most interested in speculations, the worth and 
 stability of which are yet undetermined. But an Encyclopaedia is a Histort/ of 
 human knowledge, in which therefore these intellectual embryos, which at best are 
 (as it were) but truths in the future tense, have no rightful or beseeming place. 
 This, indeed, we hold to be a principle of such paramount importance, that we take 
 the earliest opportunity of avowing our determination of a strict and systematic 
 adherence to it ; and we here give our public pledge that the Encyclopj:dia 
 Metropolitana shall be so far historical in all respects, that only what has been 
 established, or is at least already puhlici juris, and to be found in the records of 
 Science and Literature, shall form the main body of every article ; and that any 
 opinions or speculations of the writer himself shall be declared to be such, and be 
 given distinctly as a mere appendix of the article to which they belong. 
 
 7. We shall now particularize the evil to which we have been referring. From 
 the licence which the planless plan of former works allows to the separate writers — 
 in one place, instead of a systematic history of the received truths and established 
 discoveries in the department of knowledge, which was to have been exhibited, the 
 larger portion of the space is filled up with the individual writer's own crude con- 
 ceptions and prolix argumentation — while in another, on some subject of the highest 
 interest, lo ! in tarnished fragments over the numerous volumes, an old work torn 
 asunder by all the letters of the alphabet! and reminding the classical reader of the 
 decrepit Pelias, whose credulous daughters were induced by the artifices of Medea 
 to cut his aged limbs in pieces, as the sole and certain means of restoring him, like 
 another iEson, to the blooming honours of youth. 
 
 8. The ScHEJiE which we propose to substitute, or the principal outlines of the 
 Encyclopaedia Metropolitana, we now lay before the render, as follows :— The 
 work will consist of four main divisions. The first, which for the sake of dis- 
 tinction we have called the Philosophical part, comprises the Pure Sciences ; 
 and the second, or Scientific part, the Mixed and Ai)plied Sciences. The third, 
 or Biographical part, is devoted to Biography chronologically arranged. History, 
 Cin'onology, and Geography ; and the concluding or ISliseellaneous part, besides 
 being referential and supplementary to the preceding volumes, will have 
 the unique advantage of presenting to the jmblic, for the first time, a Philos;o- 
 phical and Etymological Lexicon of the English language; the citations selected 
 and arranged chronologically, yet including all the purposes of a connnon Dic- 
 tionary. The volume of Index will complete this division. It Avill be instantly 
 seen tbat the first two divisions of a work, thus arranged, will grow naturally out 
 of each other; the needful references will therefore be generally retrospective, and 
 rarely made to future volumes. In our Biographical department we shall teach the 
 same truths by example, that have been evolved in the former divisions, and 
 stimulate to the exertions that have developed them ; — while in our Miscellaneous 
 
 B 2 
 
4 ENCYCLOPAEDIA METROPOLITANA. 
 
 portion or in the Index, every word will be found in its usual alphabetical place, as 
 in any other Dictionary, with a plain reference to the volume and page containing 
 its full explanation in the present work; together with a variety of interesting 
 articles, either illustrative of the former divisions, or in their own nature miscel- 
 laneous. Each division of the work will be separately paged. 
 
 9. Such is the general outline of the proposed Scheme. The Table at page 13 
 places the principal subdivisions, likewise, befoi-e the reader's eye, with as much 
 detail as is compatible with the limits, or requisite for the purposes, of a Prospectus. 
 It will be seen, too, that a more particularized and systematic justification of the 
 principles, on which the Scheme has been constructed, will be afforded in the Pre- 
 liminary Treatise, or General Introduction to the Encyclopaedia. 
 
 10. When the work is completed, it will appear as an orderly Digest of all the great 
 points of human knowledge, and, notwithstanding its comparatively moderate extent 
 and price, must form the most perfect system of intellectual instruction and enter- 
 tainment, that has been hitherto submitted to the friends and patrons of Art, Science, 
 History, and general Literature in Great Britain. 
 
 1 1. We would place our claims to the favourable attention and patronage of the 
 public, on two grounds: 1. That the great outline of our plan is free from the 
 numerous defects and inconveniences involved in the plan of all preceding Morks of 
 tiie kind, or occasioned or permitted by it. 2. That the plan now substituted pos- 
 sesses great positive advantages, peculiar to itself. 
 
 12. From what has been already seen of our plan, in the necessary discussion of 
 its relative merits, we presume that we appropriate to the work the title of an Ency- 
 clopaedia by an especial right, and that of a Philosophical System on a plea of 
 superior propriety. Hut we cannot neglect the argument for such a work as the 
 present, which is derivable from the peculiar circumstances of our times. The 
 political changes of the world have not been more wonderful than the scientific and 
 moral revolutions that have occurred within the last few years. The new views, 
 new discoveries, and fresh facts, especially in all the different branches of Experi- 
 mental Philosophy, which every year has brought with it, are unparalleled in the 
 history of human knowledge ; and the accessions have not seldom been of such a 
 nature as no mere supplementary postscript can embrace. For in many instances 
 they affect the whole theory and consequent arrangement of the Art or Science to 
 which they belong. Our project is in this respect therefore singularly fortunate iu 
 point of time. It will have to collect and combine the rich but scattered elements 
 of future Science ; while a still more important argument for our plan and for the 
 period of its execution, will be found in the manifest tendency of all the Arts and 
 Sciences at present, from the most purely intellectual even to the labours of the 
 common mechanic, to lose their former insulated character, and organize themselves 
 into one harmonious body of knowledge. The civilized world is now doing that 
 which the ENCVCLOPiEDiA Metropolitana is preparing to do ; and for which it is 
 providing a correspondent repository. 
 
 13. The Proprietors have not disguised from themselves that their undertaking is 
 of the most arduous kind. The mass of ability requisite, will be great in proportion 
 to the originality of our plan ; and the perseverance, harmony, and punctuality, that 
 are indispensable conditions of iis success, must be commensurate with the difficulty 
 of uniting variety with system, and of reconciling selectness and calculated pro- 
 portion with universality as a whole, and fulness in each component part. If, in 
 addition to this, the amount of capital demanded and already dedicated to the one 
 purpose of securing this coalition, and of overcoming these difficulties, be considered ; 
 with the number and high character of the artists, the men of science, and men of 
 letters, on whose zealous co-operation, now pledged to us, we rest our pretension to 
 the first acts of the public favour, and our confident hopes of continued support — not 
 forgetting the relief and moral influence of a regular employment afforded during 
 all seasons of the year to so many industrious mechanics as must necessarily be 
 engaged on this work — the Proprietors of the Encyclop.«dia Metropolitana 
 dare promise themselves, that by no reflecting reader will the present prospectus be 
 deemed too serious. 
 
CONTENTS OF THE ORIGINAL EDITION. B 
 
 14. Having explained the Principles on which the EncyclopEcdia Mctropolitana 
 "was founded, we proceed to state a few facts, in reference to the manner in which 
 the First Edition of the work was executed, and the Modifications now intended 
 to be made in the Second Edition. 
 
 Id. The Encycloprcdia Mctropolitana was projected by the late eminent poet 
 and philosopher, S. T. Coleridge, It differs in its plan from other Dictionaries 
 of Universal Knowledge in being strictly methodical. The contributions of the 
 scientific and learned men by whom it was composed, are arranged, not according 
 to the letters of the alphabet which happen to form the initials of the English 
 iianies of the Treatises, but in agreement with a philosophical system, based 
 on the nature of the Subjects,— a method which causes the entire work to become a 
 rational exposition of the state of human knowledge, and the mutual dependence and 
 relative importance of its different branches. In virtue of this classification, the work 
 forms both a course of study for the scholar, and a book of reference for the man of 
 business: the former has the principles of the sciences laid before him in the phi- 
 losophical order of their natural sequence ; the latter is enabled to find readily the 
 specific information he requires on any subject that interests him. 
 
 16. The system, projected by Mr. Coleridge, was ably executed by the Editors * 
 and Authors to whom the execution of the scheme was confided. To confirm the 
 truth of this assertion, it is suflScient to refer to the names of the Authors, and to 
 state the fact, that many of the Treatises have been admitted by the Learned 
 throughout Europe to be of the highest order of merit, and to have enlarged the 
 boundaries of the scientific world, and placed their authors in the first rank of men 
 of science in the present age. 
 
 17. The following Abstract of the Contents of the Quarto Edition, 
 taken from the General Preface, will show in what manner the early professions 
 of the projector of the work were realized. 
 
 We shall speak of the four great divisions of the Encyclopaedia separately. 
 
 PURE SCIENCES. 
 
 18. The order in which these sciences are exhibited, and the plan on which the 
 Mathematical portion of ihe Encijclopadia is conceived, resemble considerably 
 the series of Elementary Treatises projected many years ago for the University of 
 Cambridge by Dr. Wood, the late Dean of Ely, and Professor Vince ; but with this 
 difference, that the present volumes are far more comprehensive in the subjects 
 they embrace, and far more elaborate and scientific in their execution, l^ut this 
 very similariiy shows that the Knci/clopadia Metropolitana has attained one of its 
 professed objects,— systematic instruction and scientific information, conveyed — not 
 in a confused mass, but in the natural sequence of the sciences. 
 
 Indeed this portion of the work has met with a degree of approbation in many 
 quarters, but especially in the University of Cambridge, which no other Encyclo- 
 paedia has ever yet received. The student who has really mastered these sciences 
 in the systematic form in which they are arranged here, will never in the course of 
 the longest life find occasion to 7/«learn any portion of what he has here acquired, 
 and will find no difficulty whatever in adding to his stores any new results which 
 the mental energy and labour of mankind may hereafter develop from principles 
 now known. It may, indeed, be safely affirmed, that any persou of good mathe- 
 matical abilities, who shall follow the course of Mathematical treatises in this Eucy- 
 clopiedia, which are so arranged that a student may pursue them even without the 
 assistance of a tutor, may become by that means a mathematician of very high 
 character, and be enabled to master the most difficult and delicate speculations of 
 continental mathematicians. 
 
 19. The names of the authors of the Treatises on Pure Mathematics are sutfi- 
 
 The ICniTOKS of the orif^inal edition of tlie I'ncyclopjpdia M(!tropolif;ina wrre — Tim Kcv. 
 KnwARi) S.MKDi.F.v, M..\., late Fellow of Sidney CoUej-e, Camliri(l;,'i- ; the Kev. Ht'r.ii .IamksRo.sk, 
 li.n., late Principal of Kind's ('ollege, London ; and the Kev. IlENKY.IoiiN Hosk, B.D., late t'ellow 
 
 of St. John's College, Camhridjje 
 
6 ENCYCLOr.EDIA METEOPOLITANA. 
 
 cient to prove that the Encijclnpadia is worthy of the present state of science, and 
 that its most important articles are contributed by tliose who have themselves been 
 foremost in the onward march of science. The elaborate Treatise on Arithmetic, 
 by the present Dean of Ely (Dr. Peacock), Lowndian Professor of Mathematics in 
 the University of Cambridge, is interesting alike to the scholar, the mathematician, 
 and the speculator in metaphysics. The brief but comprehensive Treatise on 
 Tkigonometry, by Professor Airy, now Astronomer Koyal, is of considerable 
 value from the general elegance of its demonstrations. The publications of the 
 liev. II. P. Hamilton on Analytical Geometry and Conic Sections, and that of 
 Professor Barlow on the Theory of Numbers, are so highly esteemed, that any 
 eulogium on their papers on these subjects would be superfluous. The Treatises of 
 Professor Levy on the Differential and Integral Calculus are calculated to 
 carry the student to a very high point of proficiency. The Geometry, Algebra, 
 and Geometrical Analysis complete the Volume in a manner worthy of the 
 treatises with which they are associated. 
 
 20. These sciences are, however, in some degree elementary ; and although by 
 tliem the student would be so far advanced ak to enter upon the works of some of 
 the ablest analysts, it would be unworthy of such a publication as the Encyclopoedia 
 Metropolitana to leave untouched or imperfectly treated, the more refined appli- 
 cations of the higher Calculus. It will be found, accordingly, that the highest 
 branches of mathematical analysis have been treated by writers conversant with all 
 its intricacies, and the mathematical student is furnished in them with results of far 
 greater variety and of a more subtle nature than can at present be used in the 
 application of analysis to Mixed Mathematics. 
 
 21. The Calculus of Variations, and the Calculus of Finite Differences 
 by Professor Hall, are distinguished by the clearness peculiar to his treatment of 
 these refined and subtle portions of analysis. The Calculus of Functions and 
 the Theory of Probability are the work of Professor De Morgan. The latter 
 (on a subject which has exercised the talents of the greatest mathematicians, even 
 down to the times of Laplace) is, as might be expected, one of the most complete 
 in any language. The Treatise on Definite Integrals completes the series of 
 these elaborate surveys on the higher branches of Mathematical Analysis. The 
 name of Professor Moseley is a sufRcient warrant that his Essay is also of the 
 highest character. - 
 
 22. Without wishing, therefore, to offer any undue eulogium on the Treatises 
 enumerated above, we confidently ask that portion of the public which is qualified 
 to judge of their merits, to compare the whole system of Pure MalJiematics here 
 presented to them with that in any similar work, whether of this country or of the 
 Continent, on the grounds of arrangement, clearness, ability, and completeness. 
 
 23. We must now allude to such of the Pure Sciences as are not included in the 
 Mathematical department. Sir John Stoddart has given a lucid and able summary 
 of the General Principles of Gram3IAR, or the Philosophy of Language. The 
 Logic and Phetoric of Archbishop Whately require no commendation here, as 
 they have long since been published in a separate form, and have taken their place 
 among the standard works of our language. The Treatise on Law is the work of 
 Ivichard Jebb, Esq., Professor Graves, and Archer Poison, Esq. It embraces one 
 of the most difficult portions of Philosophy — the general foundations of Law and 
 Morals; and the Editor is happy to state that testimony from the very highest 
 quarters has been given both to the profoundness of the views entertained, and the 
 ability with which they are developed. 
 
 24. In the present state of metaphysical knowledge, it would be presumptuous 
 to put forth any si/stem of Metaphysics ; but a general History of Moral and 
 Metaphysical Philosophy affords the most convenient opportunity for displaying 
 the principles on which the greatest philosophers have hitherto endeavoured to form 
 their systems, for pointing out their difficulties, and for marking how far each has 
 contributed to the progress of the science. Such a sketch, however, required the 
 hand of a master ; and the Editor confidently believes that the Treatise on Moral 
 and Metaphysical Philosophy which is here given is calculated fully to sustain the 
 
CONTENTS OF THE ORIGINAL EDITION. 7 
 
 deservedly liigli reputation of the Rev. F. D. Maurice. Of the Outlines of Thko- 
 LOGY, it does not become the Editor to say more than to acknowledge with 
 gratitude the very able assistance of Professor Corrie, to whom two chapters are 
 due. He has endeavoured to render this Treatise as practically useful as possible, 
 not only to avoid passing controversies, but to bring forward the sound and genuine 
 doctrines of the Church of England ; and perhaps he may be allowed to add that, 
 in pursuance of this object, he has spared no pains or labour. 
 
 MIXED AND APPLIED SCIENCES. 
 
 25. From Pure Mathematics we proceed in natural order to their application to 
 physical phenomena. Of these sciences, some belong to the elementary branches 
 of physical knowledge, and others to a higher and more advanced stage. Now, 
 the treatises on Mechanics, Hydrodynamics, Pneumatics, Optics, and Plane 
 Astronomy, have been written by Professor Barlow with an express view to 
 this distinction. They are elementary enough to enable any student, with a competent 
 knowledge of Pure Mathematics, to overcome their difficulties; and yet they are 
 so based on scientific principles, that they will also prepare him to enter readily on 
 the higher branches of Mixed Mathematics. In Mechanics, more especially, a 
 foundation is laid for the succeeding investigations of Physical Astronomy, which 
 is, in fact, only one of the higher branches of Analytical Physics. 
 
 26. Some of the treatises in the volumes devoted to the Mixed Sciences demand 
 a separate notice, as enlarging the boundaries of our scientific knowledge. Of this 
 class are the Treatises on Light and Sound, by Sir J. F. W. Herschel. The 
 Treatise on Light, by Sir J. F. W. Herschel, from the position it has already ob- 
 tained in the scientific world, both in England and on the Continent, cannot require 
 any recommendation here. The simple mention of Sir J. F. W. Herschel's name 
 is a sufficient recommendation to the Treatise on Physical Astronomy, and proves 
 at once that it must be an Essay of the highest order of merit, and worthy of the 
 present state of the Science ; and the conductors of this Enci/clopcedia may justly be 
 proud that that distinguished writer has contributed so largely to its pages. Put 
 although Plane and Physical Astronomy had been thus ably treated, it was con- 
 sidered that something more was required ; and the late Captain Kater kindly 
 furnished the very useful and able Treatise on Nautical Astrono3IY, a subject 
 with which his acquaintance was at once profound and pi-actical. 
 
 27. Magnetis^i and Electro-]Magnetis3I are treated by Professor Barlow with 
 the same ability and research which he has displayed in the other Essays contri- 
 buted by him ; and Galvanism, by Dr. Roget, whose scientific character is too 
 firmly established to leave any doubt as to the merit of his contributions. The 
 author of the Treatises on Electricity, Heat, and Chemistry, the late Rev. F. 
 Lunn, was one whose merits as an experimental philosopher and chemist were not 
 so extensively known as they deserved to be; but at Cambridge his acquirements 
 were acknowledged to be of the highest order. The treatises themselves, it is 
 believed, will amply justify their favourable anticipations. 
 
 28. The Third Volume of Mixed Sciences is chiefly devoted to the Fine Arts ; 
 but there are two or three Essays in the early part of the Volume which belong to 
 the more exact sciences, viz., the Essay on the Figure of the Earth, by Pro- 
 fessor Air}', the present Astronomer Royal, and his Treatise on the Tides. With 
 regard to the former much novelty was hardly to be expected ; but it is presumed 
 that this Treatise contains the most complete combination and discussion of obser- 
 vations relating to the subject hitherto produced in England. The treatise into 
 which this great mathematician has thrown all liis power is the Theory of the 
 Tides. The terms in which some of the most distinguished mathematicians of 
 Cambridge have spoken of this treatise prove that they consider it to have greatly 
 advanced the knowledge of this difficult subject. Every previous treatise on the 
 theory of the tides is entirely superseded by this production, and it will supply, for 
 many years to come, the only sound foundation of our knowledge upon this. •subject. 
 
 29. The Treatise on Political Economy was written by N. W. Senior, Esq. 
 
 30. The Treatises on Botany and Horticulture are supplied by G. Don, Esq., 
 
8 excyclopj:i)IA m7-:tropolitaxa. 
 
 ■whose profound acquaintance with every department of knowledge which belongs 
 to the vegetable kingdom is known to all botanists and florists. The Zoology 
 combines General Physiology with CoMrAP.ATivE Anatomy, and is the work of 
 ,7. F. South, Esq., Surgeon of St. Thomas's Hospital (assisted in one portion of 
 Ph5-siology by Mr. Claik and Mr. Solly). The descriptions in this Treatise possess 
 the very unusual and peculiar merit of being given by Mr. South, in every prac- 
 ticable instance, from the specimens themselves. Of the Anatomy, by Mr. South 
 and Mr. Le Gros Clark, and the Materia Medica, by Dr. G. Johnson, it may be 
 said that their names are a sufficient pledge that these Treatises are of first-rate 
 character. The Treatise on Medicine, by Dr. Eobert Williams, of St. Thomas's 
 Hospital, is an attempt to give a more philosophical view of the classification of 
 disease than has hitherto been taken in any work of modern date. To W. Bowman, 
 Esq., the Encyclopaedia is indebted for an able outline of Surgical Practice. 
 The medical volume is closed by a comprehensive Treatise on Veterinary Art, 
 by W. C. Spooner, Esq. 
 
 31. The Mi:teorology of the late Mr. Harvey, and the Crystallography of 
 Mr. Brooke, have been referred to respectively with especial commendation by 
 Professor Forbes and Dr. Whewell. The names of Mr. Phillips and Dr. Daubeny 
 will sufficiently recommend the Treatise on Geology, as exhibiting an adt^quate 
 representation of that science at the time of its publication. The Treatise on 
 Mineralogy by Mr. Brooke ; the Essays on Carpentry, by P. Nicholson, Esq. ; 
 on Fortification, by Major Mitchell and Captain Procter ; and on Naval Au- 
 CHTTECTURE, by the late Mr. Harvey, must not be passed over. The names of these 
 writers guarantee the value of their contributions. 
 
 .32 In this class of Mixed Sciences a novel feature is exhibited in the Sixth 
 Volume of the series, viz., A S\jstematic Account of the Arts atid Manufactures 
 of Great Britain. There is probably no writer who would be able to do such 
 ample justice to so extensive a range of matter, requiring both theoretical and prac- 
 tical knowledge, as its author, Mr. Barlow, but that nothing might be wanting to 
 the completeness of this portion of the work. Professor Babbage supplied a Pre- 
 liminary Discourse on the Principles of Manvfactvres ; and it may confidently be 
 asked, to what other source could the conductors of the work have appealed with 
 equal confidence on so difficult and multifarious a subject ? 
 
 HISTORICAL DIVISION. 
 
 33. It is not possible, in this rapid sketch, to specify all the papers in this 
 portion of the work ; but as nearly every contribution is assigned to its proper 
 author at the beginning of each volume, such a course is unnecessary either for the 
 information of the public, or as a tribute of respect to the distinguished authors 
 themselves. Ample care has been taken to enlist among the contributors to this 
 department writers not only of splendid endoAvments, but also of the highest attain- 
 ments in different classes of historical knowledge. There will be found among the 
 numerous writers in this division contributions from Bishop Blomfield, Dr. Whe- 
 well, Mr. Justice Talfourd, Dr. Arnold, Dean Hinds, Eev, J. A. Jeremie, Rev. G. 
 C. Eenouard, llev. J. H. Newman, Bishop Kussell, Archdeacon Hale, Dean Lyall, 
 Eev. J. B. S. Carwithen, Bishop Hampden, Eev, E. Garnet, Major Mountain, Eev. 
 J. H. B. Mountain, Captain Procter, Eev. J. E. Eiddle, Archdeacon Ormerod, T. 
 Eoscoe, Esq., W. Macpherson, Esq., Eev. E. L. Browne, Eev. H. Thomson. Eev. 
 J. G. Dowling, Eev. J. W. Blakesley, Eev. J. B. Ottley, W. Lowndes, Esq., Q.C. 
 
 34. A good work on General History has long been a great desideratum in our 
 literature. The summaries of Tytler and Eussell are too brief, and the Universal 
 History, independently of the heavy manner in which it is written, is too long. It 
 is presumed that the Historical Volumes of the Encyclopcudia Metropolitana will 
 be found to meet this want in an efficient manner. They are written by men of 
 undoubted ability ; they exhibit the history of the world at first in a series of bio- 
 graphical sketches, and then in a continuous history of each remarkable country, 
 combined with an Ecclesiastical History remarkably full and rich in the most 
 interesting epochs of the Christian Church. Dissertations of great importance in a 
 
CONTENTS OF THE ORIGINAL EDITION. 9 
 
 philosopnical point of view, such as those on Ancient Philosophy and Literature, 
 on the Crusades, the Feudal System, and the Scholastic System, are introduced into 
 the text at the most convenient periods, for the illustration of the respective subjects. 
 
 MISCELLANEOUS PORTION. 
 
 35. Although the Miscellaneous Division of this Enci/clopccdia occupies a larpfcr 
 number of volumes than any other, it requires a less extended notice. It appears, 
 however, desirable to explain in some degree the jrrinciple on which this portion 
 of the work was executed, and to indicate the authors of some of the most remark- 
 able series of papers. 
 
 The leading features in this division of the Eiwi/clopcEclia are — 
 
 1. The English Lexicon. 
 
 2. The Geography. 
 
 3. The Natural History. 
 
 4. The Miscellaneous Articles. 
 
 The universal approbation Mitli Avhich the Lexicon, compiled by Dr. IJichard- 
 son, has been received, ])recliulcs the necessity of enlarging either on the plan itself 
 or on the gigantic labour involved in its execution. The plan of giving the quo- 
 tations of each word chronolui/icaJli/ has the advantage of embodying in a philo- 
 sophical Lexicon a Histori/ of our oivn Laiu/itage. 
 
 36. For the whole of the Articles on Geography, the proprietors feel that they 
 may fairly advance the claim of having obtained the co-operation of persons more 
 than competent to bring forward whatever is most valuable for a work like tins 
 from all usually accessible sources of information. In this respect, the J^nci/clopadia 
 Metropolitana claims to take a high station among similar works ; and the names 
 of the contributors of the Articles on European and American Geocjraplnj are a 
 sufficient pledge of the ability and care with which they are executed, viz. : — T. 
 Myers, Esq., Captain Bonnycastle, K.K., C. Vignoles, Esq., C.E., II. Lloyd, Esq., 
 G. H. Smith, Esq., A. Jacob, Esq., W. D. Coolie, Esq., and Cyrus Kedding, Esq. 
 
 One class of Geographical Articles demands especial mention, and may be said 
 to be wholly without a rival in any similar work in our language, viz.: those on 
 Ancient, Oriental, and African Geographij, which were entirely supplied by the 
 Ilev. G. C. Eenouard (of Cambridge, foriV.erly Chaplain at Smyrna), and evince 
 the most extensive familiarity with every variety of language, ancient and modern. 
 The Editor believes that if these essays were collected together, and published as a 
 system of Oriental Geography, they would surpass in accuracy and value anything 
 at present existing in our own or any other European language. 
 
 37. 'J'he section of Natural History is divided chietly into Botamj and Zccloq}!. 
 In these two sciences the Genera will be found described in their alphabetical order, 
 while their scientific arrangement and the principlesof the sciences form part of the 
 treatises in the volumes devoted to the Mixed Sciences. For these tw^o departments, 
 the services of several eminent naturalists were engaged. \wBotanij, T. Edwards, 
 Esq., and G. Don, Esq., &c. In Znoloq;i, T. bVll, Esq"; F.L.S., &c., .L'E. Gray, Esq., 
 F.L.S., &c., of the British Museum ; j'. F. Stephens, Esq., and J. F. South, Esq. 
 
 38. The highly-gifted individual to whom this Encyclopadia owes so many of its 
 attractions — the late Kev. Edward Smedle.y, — enriched the Miscellaneous Division 
 with a series of articles which embody a vast store of curious and recondite infor- 
 mation, commmiicated in a manner at once instructive and agreeable. Besides 
 these articles, the Geographical Gazetteer and the Dictionan/ of Laic and Political 
 Philosop/it/, a large number of very important and valuabh' articles will be found 
 scattered through the volumes of the Miscellaneous Division. Attention may be 
 called, amongst a variety of others, to the Biblical Articles, by the Eev. T. H. Home ; 
 to the riiilological and Oriental, by the IJev. G. C. Kenouard; the Srimlljic 
 Articles, (as e. //., Dialling, Survei/ing, Weights and Measures, lSc) by Mr. liarlow ; 
 Meteoric Stones, by Professor Miller; Store and Ventilation, by C. Hood, Ksq., 
 F.R.S. ; Stucco, by T. L. Donaldson, Professor of Architecture in L'niversity 
 College, London ; the Tledogical Articles, by Arcluieacon Hale ; Essays on Engin- 
 eering, by C. Vignoles, F.sq., C- E. ; and Writing, l»y the l?ev. H. Garnet. 
 
 The Plates are for the most part the work of those two eminent engraver?, 
 
10 ENCYCLOr/EDIA METROPOLITAN A. 
 
 Messrs. Ivowry. They requii-o only a simple inspection to prove their beauty and 
 excellenci*. 
 
 Tlie Gknkral Index -was, at an early period in the publication of the Encij- 
 cJopadin, intrusted to the Rev. J. Hindle, and occupied the attention of this very 
 competent person for several years. It Avill be found to contain ample reference 
 to all that is most important and interesting. 
 
 From this review of the First Edition of the Encyclopccdia Metropolitana, we 
 proceed to describe the peculiarities of the projected Second Edition. 
 
 30. The SECOND EDITION of the Encyclopaedia Metropolitana 
 "will be handsomely printed in a series of CABINET VOLUMES, in 
 Crown Octavo, in the style shown by the Specimens on pages 14 and 15. 
 
 40. The whole work will be thoroughly Revised ; many Neav 
 Treatises will be added ; and the Articles will all be provided with 
 comprehensive Indexes, or with analytical Tables of Contents. 
 
 41. It will be abundantly illustrated by Maps, Woodcuts, and 
 EnPTavino's. 
 
 42. It will 1)G ])ublished m Weekly Parts, Price One Shilling, 
 and in Monthly Volumes, varying in price according to the numl^er of 
 Parts contained in each. 
 
 43. Methodical Arrangement of the Second Edition. — In preparing the 
 Second Edition of this Eucyclopcedia for publication, very little change will 
 be made in its System. The peculiar characteristic impressed upon it by Mr. Cole- 
 ridge — its Methodical Arrangejient — will be followed strictly. Indeed, the chief 
 difference that will appear between the arrangement of the Second Edition and the 
 First, will proceed from a more rigid adherence in the Second Edition to the jnin- 
 ciples of Method established by Mr. Coleridge, than it was possible to attain in the 
 First Edition. The work being wholly original and composed by more than a 
 hundred Contributors, it happened, during the first publication, that many of the 
 articles, either because they were not produced in proper time to be incorporated in 
 their systematic places, or for other unexplained reasons, were cast into the great 
 " Alphabetical, Miscellaneous, or Sapplementarij Division," where they are con- 
 nected together by no stronger scientific bond than their alphabetical initials. 
 But now that Ave have the whole work before us, complete (as respects the 
 First Edition), and capable of re-arrangement, we propose to rectify these acci- 
 dental departures from the true method of the Encyclopaedia, and to transfer, 
 from the Alphabetical Miscellany, every article that is capable of transference, to 
 its appropriate position in the Philosophical Classification. Thus, the Article 
 Geography, properly organized, will form a new division, complementary to that 
 on History, as was originally intended, see §8; the details of Natural History 
 will be grouped with the General Treatise on that science ; the art of Diplomacy 
 will be subjoined to the science of the Law of Nations; and so on. What remains 
 in the Alphabetical Division, after this effective re-arrangement has been made, 
 will form a Series of Dictionaries, Lexicographical, Classical, Theological, 
 Technological, &c. 
 
 4-4. Kevision and Enlargement. — Though the changes contemplated in the 
 General Si/$tem of the Encyclopaedia are not important, the improvements to be 
 made in the details will be considerable. In all possible cases, before the articles 
 are reprinted for the Second Edition, they will be thoroughly revised, either by 
 their authors or other competent persons, and Indexes and Tables of Contents will 
 be added ; the Historical series will be completed and re-arranged ; the Treatises on 
 the Natural and Experimental Sciences will either receive important amendments, 
 
PLAN OF THE TROPOSED CABINET EDlTiOX. 11 
 
 or be replaced by others entirely new ; while the Mechanical and Chemical Arts, 
 and the applications of the sciences to affairs of public utility, will be treated of in 
 the Second Edition, much more practically than they were in the First Edition. 
 
 45. Proposed Extent of the Work. — The series of scientific and historical 
 Treatises on the important Subjects comprehended in the philosophical sclieme 
 of this work (page 13), which form indispensable links of the great chain of 
 human knowledge — the Series necessary to complete the circumference of an En- 
 cyclopedia — cannot be compressed into fewer than Eighty Cabinet Volumes. 
 That is the minimum extent. But since the methodical plan of the work, as de- 
 veloped in this Prospectus, will permit at all times of the incorporation of such ad- 
 ditional Treatises, as may be requisite to keep its scientific principles and historical 
 facts in accordance with the progress of the age, — a permission of which the con- 
 ductors will freely avail themselves, — it is impossible to state what may be the 
 maximum number of its volumes. An Encyclopoedia intended to reflect always the 
 existing state of human knowledge, " to act," (in the language of Mr, Coleridge,) 
 '* at once as a reservoir and a fountain, — to receive perpetual accessions of knowledge 
 from the genius of the age, and to yield the knowledge again in willing abundance," 
 — such a work can never be elfectually " completed." That word applies with as little 
 propriety to such an Encycloptedia, as it does to the Times Newspaper or the Philo- 
 sophical Transactions ; for, like those celebrated journals, this Encyclopscdia will 
 be at all times ready to incorporate an account of every important Event and new 
 Principle that Time and Discovery may furnish, and for which its philosophical 
 system provides an adequate Repository. 
 
 46. Improved Plan of Publication. — A great alteration, and, it is hoped, an 
 important improvement, will be made in the method of publishing the Second 
 Edition, as contrasted with the method adopted for the first edition of this Ency- 
 clopedia. The PARTS of the Cabinet Edition will not, like the Parts of the 
 Quarto Edition, contain letter-press and engravings belonging to difierent subjects 
 or ditferent Divisions of the Encyclopaedia, forming a heterogeneous and unreadable 
 mixture of fragments of many Treatises; but each. PART Avill relate only to one 
 subject ; and whenever it is possible, each VOLUME of the Cabinet Edition will 
 embrace all that relates to one subject. That, however, will necessarily depend 
 upon the nature of the Subjects and the consequent extent of the Treatises. 
 Very frequently several will be comprised in one Volume, and occasionally an 
 important subject, — the principles of a leading Science, or the History of a great 
 nation, — will occupy two volumes. But care will be taken to ensure a due pro- 
 portion in size among the several Treatises, to avoid unnecessary prolixity, to 
 combine comprehensiveness in matter with convenience in form, and to avoid the 
 incongruous binding together of Treatises on irrelative Subjects — such, for example, 
 as occurred in Vol. 5 of the First Edition, where the Treatises on the Fine Arts 
 were combined with two profound Mathematical Treatises belonging to the 
 Department of Astronomy. 
 
 47. Advantages to the Subscribers. — Those who subscribed to the original 
 edition, and who remember how it was contrived to convert the most Methodical of 
 Encyclopedias into the most lisimethodical of Publications, will readily recognise 
 the importance of an alteration, which insures to tue Subscriber to the 
 Second Edition the possession of a complete readable portion of the work in 
 recompense for every Subscription he is required to make. 
 
 48. Order OF Publication. — It seems not unnecessary to call the attention of 
 intending Subscribers to the difference that exists between the order in which the 
 Subjects occur in the general system of this Encyclopedia and the order in which 
 it may be advisable to publish the Treatises on those subjects. In consequence of 
 the different amount of corrections that will be required l)y the various Treatises 
 that compose the Encyclopedia, and the circumstance that many Treatises on subjects 
 that demand extensive investigation must l)e written entirely anew, — it would be 
 impossible, without submitting to great delay and irregularity, to publish the 
 revised Articles and new Treatises in Weekly Parts, in tlie exact order in which 
 the subjects occur in Mr. Coleridge's methodical plan. Neither is it desirable 
 
1 2 ENCYCLOPAEDIA METROPOLITANA. 
 
 to adhere to that order pertinaciously, because it ^^ould not be agreeable to 
 the great body of the SUBSCRIBERS to so comprehensive a work as this 
 EscYCLOPiEuiA, to receive, for months together, a series of Weekly Parts 
 relating solely to Mathematics, or to Geography, or to History, or indeed to anij 
 Department, in its order — all other subjects being, for the time, systematically excluded. 
 A proceeding of that sort could hardly fail to excite dislike or indifference to the 
 -work in the" Families of many of tlie Subscribers. The Proprietors consider, 
 therefore, that they will consult the general convenience, both of the Authors 
 and the Subscribers, by publishing the Treatises in an indeterminate order, — giving 
 History, Science, and Art alternately, but carefully indicating on the title-page of 
 each Volume its exact place in the entire System, in accordance with the Plan 
 given in page 13. In order, however, to prevent mistakes, every Part and 
 Volume of the work, as published, will be marked with a running Number, 
 simply to indicate the order of Publication, and irrespective of the ultimate Philo- 
 sophical Arrangement of the articles. The Parts that constitute a Volume will be 
 published as near together as circumstances permit, and, from time to time, 
 General Title Pages and Tables of Contents will be supplied, to complete the 
 Volumes of the several Divisions. 
 
 49. Regularity of Publication. — The vast amount of original writing of the 
 highest class, in every department of literature and science, which is comprehended 
 in the First Edition of this Encyclopgedia, and the proved excellence of its me- 
 thodical plan, Avill so greatly facilitate the preparation of the Cabinet Edition, 
 that the Conductors trust to be enabled to issue the Weekly Parts in uninterrupted 
 succession, — correcting in the work, as they go on, what requires correction ; 
 retrenching what is superfluous ; and supplying what is deficient ; so as to bring the 
 whole more strictly into accordance with Mr. Coleridge's great idea of the essen- 
 tials of an Encyclopaidia, and producing, if possible, a " System of Universal 
 Knowledge," more philosophical in its plan, more ably executed in its details, 
 more convenient in size, and more economical in price, than any work of the kind 
 that has ever hitherto been produced. 
 
 50. AVe conclude this Prospectus with a short extract from the Preface to the 
 First Edition of the Encyclopaedia : — 
 
 " The foregoing enumeration of the principal parts of the Encyclopgedia em- 
 bodies all the observations which the Editor considers it necessary to make in 
 recommending the work to the patronage of the public. The exertions made by 
 the Proprietors to procure the just fulfilment of the high expectations formed of 
 the work, and of the promises they had made, as well as the perseverance with 
 which they have conducted this important publication to its completion, amidst the 
 many obstacles which must necessarily arise in so extensive an undertaking, entitle 
 them to high consideration from that portion of the Public which is interested in 
 works of a sterling and substantial character. From the present position of 
 Literature, and tltc system now in fashion of' publishing small and superjicial ivorks 
 ivhich may be cheaply produced, and are really of no intrinsic value, it is probable 
 that a long period must elapse before any similar undertaking will be entered upon, 
 from the enormous oixtlay of capital it requires, and theuncertainty of remuneration 
 which it offers. It is hoped, therefore, that this Great National Work, for such 
 it really is, may meet with that patronage which the Proprietors feel confident it 
 fairly and fully deserves. They feel assured that, whether it be viewed as a whole 
 or in its separate divisions, it embodies a mass of information at once extensive, 
 accurate, and scientijically arranged, which must place it in a pre eminent and 
 triumphant position. Whatever its measure of success may be in a pecuniary point 
 of view, they may justly feel a high gratification in having been instrumental, 
 under Providence, in bringing to a successful termination a work ivhich, ivhether its 
 Literary merit or the soundness of its Moral and Religious views be 
 regarded, must ever be considered as an inestimable benefit to their Country 
 
 AND A PER3IANENT ORNAMENT TO ITS LITERATURE." 
 
 London f October, 1849. 
 
PLAN OF THE ENCYCLOPiEDIA METROPOLITANA. 
 
 The INTRODUCTION.— On the Laws and regulative Principles of EOrCATIOX; or in the 
 Language of the Schools, the Elements of Mlil'HODOLOGY. 
 
 FIRST DIVISION. 
 
 PURE SCIENCES. 
 
 Skction I. 
 Formal Sciences. 
 
 Philosophy of Language. 
 Logic, 
 llhetoric. 
 Mathematics : — 
 
 Geometry. 
 
 Arithmetic. 
 
 Algebra. 
 
 Geometrical Analysis. 
 
 Theory of Numbers. 
 
 Tiigonometry. 
 
 Analytical Geometry. 
 
 Conic Sections. 
 
 Differential and Integral 
 Calculus. 
 
 Calculus of Variations. 
 
 Calculus of Finite Dif- 
 ferences. 
 
 Calculus of Functions. 
 
 Theory of I^obabilities. 
 
 Definite Integrals. 
 
 SECTirN II. — Real Sciences. 
 
 Moral and Metaphysical 
 
 Philosophy. 
 Law : — 
 General Principles of Law. 
 Roman Law. 
 English Law — 
 
 Laws of England. 
 
 Laws of Ireland. 
 
 Laws of Scotland. 
 
 Colonial Las\ . 
 Canon Law. 
 Politics : — 
 
 Law of Nations^ 
 
 Diplomacy. 
 Political Philosophy — 
 
 Statistics. 
 Political Economy — • 
 
 Commerce. 
 Theology :— 
 
 Natural Theology, 
 llvidencesof Revelation. 
 Scripture Doctrine. 
 
 liiblical Literature. 
 
 liiblical Antiquities. 
 
 Religions and Religious 
 Customs. 
 
 SECOND DIVISION. 
 
 MIXED AND APPLIED 
 SCIENCES. 
 
 Section I. 
 Mf.chanicai, 1'hii.osophy. 
 {Mixed Mat/wmatics). 
 Mechanics. 
 Hydrostatics. 
 Pneumatics. 
 Optica. 
 
 Astronomy : — 
 
 Plane Astronomy. 
 
 Nautical Astronomy. 
 
 Physical Astronomy. 
 Figure of the Earth. 
 Tides and Waves. 
 
 1 Section II. 
 
 Experimental Philosophy. 
 1 Magnetism. 
 
 I Electro-Magnetism. 
 
 Electricity. 
 
 Galvanism. 
 
 Heat. 
 
 Light. 
 
 Chemistry. 
 
 Sound. 
 
 Meteorology. 
 
 Section III. — The Fine Arts. 
 Architecture. 
 Sculpture. 
 Painting. 
 Heraldry. 
 Numismatics. 
 Poetry. 
 Music. 
 Engraving. 
 
 Section IV. 
 The Useful Arts. 
 Agriculture. 
 Horticultuie. 
 Floriculture. 
 Arboriculture. 
 Carpentry and Joinery. 
 Fortification. 
 Engineering. 
 Naval Architecture. 
 Manufactures. 
 I^Iechanical Arts. 
 Chemical Arts. 
 
 Section V. 
 
 Natural History. 
 Inanimate : — 
 Crystallography. 
 Mineralogy. 
 Geology. 
 Insentient : — 
 
 Botany. 
 Animate : — 
 Zoology. 
 Physiology. 
 
 Comparative Anatomy. 
 ^'e^tebrals : 
 
 Mammalia, i Reptiles. 
 
 Birds. I Fishes. 
 
 Invertebrals : 
 
 Molluscs. Spined Skins 
 
 Insects. Sea Nettles. 
 
 Crustaceans. Infusories. 
 
 Arachniilans. I'olyps. 
 
 Myriapods. 
 
 Section VI. — Applications ok 
 Natural History. 
 Anatomy. 
 Materia Mcdica. 
 Pharmacy. 
 .Medicine. 
 Surgery. 
 Vttlerinarv Art. 
 
 THIRD DIVISION. 
 
 HISTOKV 
 AND BIOGHAPHV. 
 
 Introduction : — 
 
 On the Uses of History. 
 Chronology. 
 Chronological Tables. 
 
 ARCHiEOLOOY. 
 
 Ethnology. 
 
 -Incient History : — 
 Sacred History. 
 'I'he Jews. 
 (Greece. 
 
 Greek Literature. 
 Greek Philosophy and Art. 
 Ancient Oriental .Nations. 
 Rome. 
 
 Roman Literature. 
 Roman Philosophy. 
 Classical Antiquities. 
 Heathen Mythology. 
 
 Middle Aoes. 
 
 Modern History : — 
 The Christian Cluucli, 
 Greek Empire. 
 Ottoman Empire. 
 The Crusades. 
 Italy. 
 Germany. 
 France. 
 Spain. 
 Portugal. 
 Netherlands. 
 Switzerland. 
 Britain. 
 America. 
 India. 
 
 FOURTH DIVISION. 
 
 c;eography. 
 
 Physical Geooraphv. 
 
 Political Geooraphy : — 
 
 I'Uiropean. 
 
 American. 
 
 Oriental. 
 
 African. 
 
 (Classical. 
 British Topography. 
 
 FIFTH DIVISION. 
 LEXICOGRAPHICAL. 
 
 English Lexicon, &.c. &c. 
 See Prospectus, ^ 4.i. 
 
 &c. 
 
 fJENKKAL INDEX. 
 
14 
 
 SPECIMEN PAGE OF THE IIISTORICAL DIVISION. 
 
 Alexander's 
 favour to the 
 Jews. 
 
 His 
 
 behaviour 
 to the 
 Samaritans, 
 
 derived from them the greatest encouragement to carry on the war 
 against Darius, not doubting but that he was the person described in 
 the prophetic books. 
 
 At his departure these circumstances so effectually recommended the 
 Jews to the fovour of Alexander, that when they petitioned him to 
 allow them to live under their own laws, and in the free exercise of 
 their religion, and further to be exempted from tribute every seventh 
 year, because their law forbade them to cultivate the soil in the year 
 of the sabbath, he immediately complied with their request. The Jews 
 further implored his protection for their brethren whom he would find 
 settled in Babylon; and many of them, won by his kindness, enlisted 
 as soldiers in his service, and accompanied him on his expedition. 
 
 The Samaritans envying the Jews the favour they had so unexpect- 
 edly gained, and jealous of the distinction conferred upon them, thought 
 by a similar line of conduct to gain as much influence with the king. 
 They met him as he returned from Jerusalem in a solemn religious 
 procession, and professing their kindred w4th the Hebrews, sought 
 from him a grant of the same privileges which he had given to their 
 brethren. Alexander excused himself from paying attention to their 
 request till after his return from Egypt ; but, during his absence, a 
 rebellion taking place in the city, in which Andromaclms, the governor, 
 ]:)orished, at his return he caused all those who were concerned in the 
 disturbance to be put to death, and driving out the Samaritans, planted 
 their cit}' with Macedonians ; those wdio survived retired to Shechem, 
 imdcu' Mount Gerizim, which from that time became the metropolis of 
 tiie Samaritan sect, and continues so to this day. The eight thousand 
 Samaritans who had joined Alexander at Tyre, and had been with him 
 ever since, he settled in Thebais, the remotest province of Egypt, lest 
 their presence in Samaria should revive the mutinous spirit of their 
 countrymen. This treatment contrasts strikingly with that which the 
 Jews subsequently received, for when Alexandria was built, he settled 
 therein many of that nation, giving them gi*eat privileges, and allowing 
 them not only the use of their own laws and religion, but also the 
 enjoyment of equal franchises and liberties with his owai people, the 
 Macedonians. 
 
 It does not fill within our province to pursue the narration of 
 Alexander's conquests, or to trace him in his rapid progress to the 
 highest pinnacle of martial glory ; one part, however, of his character 
 is so closely connected with the occurrences related to have taken place 
 on his arrival at Jerusalem, that we cannot forbear stopping to direct 
 the reader's attention to it. It has often created surprise that a man 
 of Alexander's strength of mind, should have been guilty of such folly 
 and weakness as to feign himself to be the son of Jupiter Amnion, and 
 to undertake a most laborious expedition to his Temple, wdiich was 
 situated in the midst of the deserts of Lybia, and tw^elve days journey 
 from Memphis, for no other purpose than that of procuring himself the 
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ENCTCLOPiEDIA METEOPOLITMA : 
 
 OR, 
 
 Sgstcm of ^nibcrsHl BnotoUtige 
 
 ON A METHODICAL PLAN 
 
 PEOJECTED BY SAMUEL TAYLOR COLERIDGE. 
 
 SECOND EDITION, REVISED. 
 
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 LOGIC. 
 
 7 
 
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 LONDON: 
 
 PUBLISHED BY JOHN JOSEPH GRIFFIN & CO. 
 
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 AND RICHARD GRIFFIN & CO. GLASGOW. 
 
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 ILa/v 
 
l\ 
 
 .1 vU-^ 
 
 LOGIC. 
 
 By RICHARD WHATELY, D.D, 
 
 ARCHBISHOP OF DUBLIN. 
 
 UEPRlNTEl) FKOM TUE ORIGINAL EDITION. 
 
 IV5363056 
 
CONTENTS.* 
 
 INTRODUCTORY SECTION. page 
 
 Definition of Logic, ....... 1 
 
 HisTORT OF Logic, ....... 1 
 
 In early times Logic not distinguished from Metaphysics, . . 1 
 
 Zeno the Eleatic, the earliest writer on Logic, . . .2 
 
 Review of his work on the subject, . ... 2 
 
 Euclid of Megara — Antisthenes, . . . . .2 
 
 Archytus, the inventor of the Categories, . ... 3 
 
 Aristotle, the real founder of the Science, ... .3 
 
 Galen, Porphyry, Boethius, ...... 4 
 
 The Schoolmen, ....... 4 
 
 Bacon, ........ 4 
 
 His censure of the Logical pursuits of the Schoolmen, . . 4 
 
 Locke, ........ 4 
 
 His objection to the Science, as unserviceable in the discover}' 
 
 of truth, founded on misapprehension, . . .4 
 
 Watts, ........ 4 
 
 Character of his work on "The Right Use of Reason," . 5 
 
 Mistaken views of many objectors to Logic, . . .5 
 
 Replies to certain objections, . . . . .6 
 
 Difficulty of introducing the Student to the subject in a clear and 
 
 satisfactory manner, ...... 7 
 
 Exposition of a difficulty common to all abstract i)ursuits, namely, 
 
 that of perceiving the ultimate use of abstract principles, . 7 
 
 Exemplified in reference to the science of Chemistry, . . 7 
 
 This difficulty obviated in Chemistry by substituting the Analytical 
 
 for the Synthetical mode of procedure, .... 7 
 It is therefore considered advisable to introduce Logic in the same 
 
 manner, ........ S 
 
 A.NALTTICAL SlvETCH OF THE LOGICAL StSTEM, . . .8 
 
 The reasoning process the same in all cases, . . .8 
 Mathematical, Theological, Metaphysical, and Political Reason- 
 ing, not different kinds, . . . . . 8 
 
 Logic, a method of unfolding and analyzing our Reasoning, cot a 
 
 peculiar method of Reasoning, . . . „ . 9 
 Desirableness of some general rules for Reasoning, applicable to all 
 
 cases, ........ 9 
 
 Conclusions are deduced from two other Propositions, called Premises, 10 
 
 An Argument stated regularly and at full length, is called a Syllogism, 10 
 
 A Premiss placed (7/i!er its Conclusion is called the iJeason of it, . 10 
 
 * The author of the Treatise on Logic is not accountable for the contentj of this 
 Synopsis.— Editor Ency. Met. 
 
vi CONTENTS. 
 
 PAGE 
 
 10 
 10 
 
 11 
 11 
 
 Causal Conjunctions and their use, .... 
 Illative Conjunctions, ..... 
 
 Apparent Arguments, ..... 
 
 Proof, Cause, Reason, ..... 
 
 Test of the validity of an Argument, — not whether the Conclusion 
 
 be true, but whether it follows from the Premises, . .11 
 
 Analysis of some clear and valid Arguments, to observe in what 
 
 their Conclusiveness consists, . . . . .11 
 
 The principle on which Syllogisms are constructed is the Universal 
 
 Principle of Reasoning, . . . . . .12 
 
 What is meant by Logical Reasoning, . . . .12 
 
 Aristotle's Dictum de omni et nulla, the keystone of his whole Logical 
 
 system, ..... ... 13 
 
 Professor Campbell's misapprehension of Aristotle's Dictum, . 13 
 
 Dugald Stewart's objections to the Dictum also founded on misap- 
 prehension, . . . . . . .13 
 
 The objections refuted, . . . . . .14 
 
 Abstracting process, by which any Particular Argument may be 
 
 brought into the most General Form, . . . .14 
 
 Advantages of Arbitrary unmeaning Symbols, . . .15 
 
 The Conclusiveness of a Syllogism, or Valid Argument, is evident 
 
 from the mere /br??i of the expression, . . . .15 
 
 Apparent (Unsound or Fallacious) Arguments cannot be reduced 
 
 into the form of a Syllogism ; for when stated in the nearest 
 
 approachable form, their fallaciousness become evident, . .15 
 
 Examples given, • . . . . .16 
 
 Terms explained : a Distributed Term is one that is taken universally, 
 
 so as to stand for every thing it is capable of being applied to ; an 
 
 Undistributed Term is one that stands for a part only of the things 
 
 signified by it, . . • . . . .16 
 
 Signification of the " middle term" and its "non-distribution," . 16 
 Indefinite Propositions, . . . . . .17 
 
 Universal and Particular Propositions, . . . .17 
 
 Quantity and Quality of Propositions, . . . .17 
 
 The Distribution of the Predicate is implied in negative Propositions, 
 
 and its Non-distribution in afiirmatives, . . . .18 
 
 Distribution of the Middle Term, . . . . .18 
 
 Universal applicability of Aristotle's Dictum, . . .18 
 
 Of Predication, . . . . . . .19 
 
 Terms that denote a single Individual, . . , .19 
 
 Common Terms, which denote one Individual of a whole class, . 19 
 Common Terms are afiirmatively predicable, . . .19 
 
 Abstraction and Generalization. — Abstraction does not necessarily 
 
 imply Generalization ; though Generalization implies Abstraction, 20 
 The Notion expressed by a Common Term is merely an incomplete 
 
 Notion of an Individual, . . . . . .20 
 
 Generalization may be indefinitely extended by Abstraction applied 
 
 to Common Terms, . ... . .20 
 
 The employment of this faculty at pleasure has been rightly regarded 
 
 as characteristically distinguishing the human mind from that of 
 brutes, . . • • • • • .21 
 
 Arbitrary Abstractions adapted to special subjects of Reasoning, . 21 
 Classifications for special objects, . . . . .21 
 
 Narrowness of mind, . .... .21 
 
 The Quality of our Reasoning depends upon our ability to Abstract 
 
 from any subject a Middle Term suitable to the occasion, . 22 
 
CONTENTS. vii 
 
 PAQE 
 
 CHAPTER I. 
 OF THE OPERATIONS OF THE MIND AND OF TERMS. 
 
 § I. — Three Operations of the Mind are concerned in Argument, . 23 
 
 1. Siniple Apprehension, . . . . .23 
 
 2. Judgment, ....... 23 
 
 3. Reasoning or Discourse, . .... 23 
 
 § II. — Language affords the Signs by which these Operations of the 
 
 Mind are expressed and communicated, . . .23 
 
 An Act of Apprehension is called a Term, . . .23 
 
 An Act of Judgment is called a Proposition, . . .23 
 
 An Act of Reasoning is called an Argument or Syllogism, . 23 
 Language is employed for various purposes. Logic is the art 
 
 of employing Language properly for the purpose of Reasoning, 24 
 A Syllogism is resolvable into three Propositions, each Proposi- 
 tion containing two Terms, the Subject and the Predicate, 24 
 
 § III.— Of Terms, ....... 24 
 
 A Term may consist either of one word or of several. Not ever}- 
 word is capable of being employed as a Term : A Noun may 
 be by itself a Term : A Verb is resolvable into the Copula 
 and Predicate, ..... 
 
 An Adjective cannot be made the Subject of a Proposition, but 
 is often employed as a Predicate, 
 
 Singular and Common Terms, .... 
 A Singular Term stands for one Individual, 
 A Common Terra stands for several Individuals, 
 
 The Notions expressed by Common Terms are formed by the 
 faculty of Abstraction, .... 
 
 Generalization and Abstraction differ, 
 § IV Species, Genus, Differentia, Property, Accident ; the rela- 
 tion and significance of these words, . 
 
 Classes of Predicables, .... 
 
 § V. — Subaltern Genus or Species, is a Genus w^hich is also a Species, 26 
 
 Summum ( the highest) Genus, is a Genus which is not considered 
 
 as a Species of any thing, . . . . .27 
 
 Infima (the lowest) Species, is a Species which is not considered 
 
 as a Genus of any thing, . . . . .27 
 
 Proximura Genus and Remote Genus, . . . .27 
 
 Differentia distinguished from Property, . . .27 
 
 Accidents, separable and inseparable, . . . .27 
 
 Prcdicable and its Classes, are relative Terms, . , 27 
 
 Common Terms have no Real Thing existing in nature corre- 
 sponding to them, . . . . . .28 
 
 § VI. — Logical Division, . . . . . .28 
 
 An Individual is so called because it is incapable of Logical 
 
 Division, . . . . . . .28 
 
 Logical Division is a metaphorical expression, signifying the 
 Separate enumeration of several things signified by one com- 
 mon name. It is opposed to Generalization, . . 28 
 
 There arc Three Rules for Logical Division : — . .28 
 
 1. Each of the Parts, or any of tliem short of a//, must contain 
 
 less than the thing divided, . . . .28 
 
 2. All the Parts together must be exactly equal to the thing 
 
 divided, . . . . . . .28 
 
 24 
 
 25 
 25 
 25 
 25 
 
 25 
 
 26 
 26 
 
viii CONTENTS. 
 
 PAOB 
 
 3. The Parts, or Members, must be opposed to one another, 28 
 Cross Divisions, , . . . . .29 
 
 Logical Division differs from JNIetaphysical and Physical Division, 29 
 § VII. — Definition, a word which literally signifies " laying down a 
 boundary ;" used metaphorically in Logic to signify an 
 expression which explains any Term, so as to separate it from 
 every thing else, as a boundary separates fields, . . 29 
 
 Nominal and Real Definitions, . . . .29 
 
 Accidental and Essential Definitions, . . . .30 
 
 An Accidental Definition is commonly called a Description, . 30 
 Definitions are also Physical and Logical, . . .30 
 
 Definitions are divided into Nominal and Real, according to the 
 object accomplished by them ; into Accidental, Physical, and 
 Logical, according to the means employed hj each for accom- 
 plishing the respective objects, . . . .30 
 Uses of the several kinds of Definitions, . . .31 
 Three Principal Rules for Definition : — . . .31 
 L It must be adequate, . . . . .31 
 
 2. It must be plainer than the thing defined, . .31 
 
 3. It must be couched in a convenient number of appro- 
 
 priate words, . . . . . .31 
 
 CHAPTER II. 
 OF PROPOSITIONS. 
 
 § I. — The Second Part of Logic treats of the Proposition; which is 
 
 '■'■ Judgment expressed in words," . . . .32 
 
 A Proposition is defined logically " a sentence indicative," i.e. 
 
 afiirming or denying, . . . . .32 
 
 Propositions are divided into Categorical and Hypothetical, 32 
 Categorical Propositions are divided into Pure and Modal, . 32 
 Propositions are divided, according to their Quality, into 
 
 Afiirmative and Negative, . . . . .32 
 
 They are further divided, according to their Quantity, into 
 
 Universal anu Particular, . . . .33 
 
 Symbols (A. E. I. 0.) are used to indicate the Four Kinds 
 
 of Pure Categorical Propositions, . . . .33 
 
 § n. — Indefinite Propositions, . . . . .33 
 
 Matter of a Proposition, . . . . .33 
 
 Signs, Universal and Particular, . . , .33 
 
 Singular Propositions, are commonly Universals, but some- 
 times Particular, . . . . , .33 
 Distribution of Terms : — 
 
 1. All universal Propositions (and no particular) Distribute 
 
 the Subject, . . . . . .34 
 
 2. All negative Propositions (and no affirmative) Distribute 
 
 the Predicate, . . . .34 
 
 § III. — Of Opposition, ....... 34 
 
 Two Propositions are said to be Opposed to each other, when, 
 having the same Subject and Predicate, they differ in 
 quantity, or qualitjj, or both, . . . .34 
 
 Four different kinds of Opposition : — Contraries, Sub-con- 
 traries, Subalterns, and Contradictories, . . .34 
 Scheme of the different kinds of Opposition, . . 35 
 
CONTENTS. ix 
 
 Explanation of the Symbols in the Scheme of Oppositions 
 
 A = Universal Affirmative Proposition. 
 E = Universal Negative Proposition. 
 I = Particular Affirmative Proposition. 
 O := Particular Negative Proposition, 
 n = Necessary matter, 
 i :=: Impossible matter, 
 c = Contingent matter, 
 f ^ Falsum. The Proposition is false. 
 V = Verum. The Proposition is true. 
 
 § rV". — Of Conversion, ..... 
 
 A Proposition is said to be Converted when its Terms are 
 
 transposed — Simple Conversion, 
 Illative Conversion, 
 Conversion by limi':ation, 
 Conversion per accidens, 
 Conversion by negation, 
 Conversion by contra-position, 
 Convertible Terms, 
 
 PAGE 
 
 35 
 
 35 
 35 
 36 
 36 
 36 
 36 
 36 
 
 CHAPTER m. 
 
 OF ARGUJMENTS. 
 
 § I. — Argument is the Third Operation of the Mind, viz., Reasoning 
 (or Discourse) expressed in Words. An Argument stated at 
 full length and in its regular form is called a Syllogism : the Third 
 Part of Logic therefore treats of the Syllogism, . . 37 
 
 Argument defined, . . . . . .37 
 
 Syllogism defined, . . . . . .37 
 
 Explanation of the words Question, Conclusion, Inference, 
 
 Reason, Premises, . . . . .37 
 
 Causal and Illative Conjunctions, . . . .37 
 
 § II. — Aristotle's " Dictum de omni et nullo" — " "Whatever is predicated 
 of a Term distributed, whether affirmatively or negatively, may 
 be predicated in like manner, of every thing contained under it," 37 
 Axioms or Canons by which the validity of Pure Categorical 
 
 Syllogisms is to be proved, . . . .38 
 
 1st. If two Terms agree with one and the same third, they 
 agree with each other: On this Canon rests the 
 validity of Affirmative Conclusions, . . .38 
 
 2d. If one Term agrees and another disagrees with one and 
 the same third, these two disagree with each other: On 
 this Canon rests the validity of Negative Conclusions, 38 
 Rules or Cautions for ascertaining whether these Canons liave 
 been strictly observed or not, and by which all Syllogisms are 
 to be tried, . . . . . . .88 
 
 1st. Every Syllogism has three, and only three Terms, . 38 
 2d. Every Syllogism has three, and only three Propi)si- 
 tions, viz., the major Premiss, the minor Premiss, and 
 the Conclusion, . . . . .38 
 
 3d. If the middle Term is ambiguous, there are in reality 
 
 two middle Terms in sense, though but one in sou7id, 38 
 4th. No Term must be distributed in tlic Conclusion which 
 
 was not distributed in one of the Premises, . 39 
 
X CONTENTS. 
 
 5tli. From negative Premises you can infer nothing, 
 6th. If one Premiss be negative, the Conclusion must be 
 negative, 
 
 § m.— Of Moods, .... 
 
 § IV.— Of Figure, .... 
 
 § V, — OSTENSIVE KeDUCTION of SYLLOGISMS, 
 
 § VI. — Reductio ad Impossibile, 
 
 § VII. — Names of the Moods, 
 
 Explanation of the consonants contained in the table of 
 Moods and Figures, page 41, 
 
 PAGE 
 
 39 
 
 39 
 40 
 40 
 43 
 44 
 45 
 
 45 
 
 CHAPTER ly. 
 
 OF MODAL SYLLOGISMS, AND OF ALL ARGUMENTS BESIDES 
 REGULAR AND PURE CATEGORICAL SYLLOGISMS. 
 
 § I. — Of Modals, ..... 
 
 § 11. — Of Hypothetic als, .... 
 
 § ni. — Of Conditionals, .... 
 
 Antecedent and Consequent Propositions, 
 Conditional Syllogisms are Constructive or Destructive, 
 
 § IV. — Of Disjunctives, .... 
 
 § V. — The Dilemma, ..... 
 
 1. Simple Constructive Dilemma, 
 
 2. Complex Constructive Dilemma, 
 
 Dilemmas, improperly so called, 
 The True Dilemma defined, 
 
 3. Destructive Dilemma, 
 
 § VI. — Reduction of Hypotheticals, 
 
 § VII. — Of Enthymeme, Sorites, »S;c. 
 
 1 . The Euthymenie is a Syllogism with one Premiss suppressed, 
 
 2. A Sorites is a brief form of stating a series of Syllogisms, 
 
 in which the Conclusion of each is made the Premiss of 
 the next, till you arrive at the main Conclusion of all, 
 Inductive Arguments. A priori reasoning, 
 
 3. Abbreviations. Equivalents, . . . . 
 
 4. Syllogisms, apparently faulty, but which are reducible to 
 
 a regular form, ...... 
 
 § Vin. — Considerations respecting the proper province of Logic, 
 Discredit unjustly brought upon the Science, 
 
 46 
 
 46 
 
 47 
 47 
 48 
 
 49 
 49 
 49 
 49 
 50 
 50 
 50 
 
 51 
 
 52 
 
 52 
 
 52 
 53 
 53 
 
 53 
 
 54 
 55 
 
 CHAPTER V. 
 OF FALLACIES. 
 
 Introduction, ........ 56 
 
 Fallacy defined, .... ... 56 
 
 A familiarity ^vith Logical principles begets a habit of clear and 
 
 sound Reasoning, . . . . . . .56 
 
 Fallacies have too often been treated in a loose and rhetorical style 
 
 of writing, instead of being discussed on strictly Logical principles, 56 
 
CONTENTS. Xi 
 
 FAOB 
 
 § I. — Division op Fallacies, ...... 57 
 
 The common division of Fallacies into those in the Words, 
 1)1 dictione, and those in the Matter, Extra dictionem, not 
 satisfactory, . . . . . .57 
 
 Division into Logical and Non-Logical, . . .58 
 
 § II. — Logical Fallacies, — where the Conclusion does not follow 
 
 from the Premises, . . . . . .59 
 
 1 . Purely Logical Fallacies, . . . . .59 
 
 2. Semi-Logical Fallacies, . . . , .59 
 Complaint against Logic, that it does not teach, but jjie- 
 
 supposes, the sense of Terms, . . . .59 
 
 Familiar terms often misapplied from misapprehension of 
 
 their exact meaning, . . . . .60 
 
 § in. — jNIaterial or Non-Logical Fallacies, — where the Conclusion 
 
 does follow from the Premises, . . . . .60 
 
 1. When the Premises are such as ought not to have been 
 assumed, ...... .60 
 
 2. When the Conclusion is not the one required, but irrelevant, 60 
 Ignoratio elenchi, — where your argument is not the elenchus 
 
 {i.e. \)Yoo{ of the contradictor)/) of your opponent's assertion, 
 but the proof of something resembling it, . . . 60 
 
 Non causa p7-o causa : 
 
 A non tali pro tali, arguing from a case not parallel as 
 
 if it were so, ..... 60 
 
 A non vera pro vera, unfair assumption cf a Premiss 
 
 (Falsity) . . . . . .60 
 
 Petitio principii, — Begging the Question — Arguing in a Circle, 61 
 
 § IV. — Tabular Scheme of Fallacies, . . . .62 
 
 § V. — Importance and Difficulty of detecting and describing 
 
 Fallacies, . . ..... 63 
 
 Necessity of guarding against Fallacies, not only when used 
 designedly by a Sophist, but when occurring in our solitary 
 Ueasoning, . . . . . . .63 
 
 Dangerous influence of Ambiguous Words over the Thoughts, 63 
 Example : fallacy attending the use of the word Plain, . 63 
 Second Example : the word Heavy, . . .63 
 
 Influence of Analogical Terms in leading men into erro- 
 neous notions in Theology, . . . .64 
 
 § VI. — The Difficulty of Detecting and Exposing Fallacy is 
 greater than that of Cojiprehending and Developing a 
 process of Sound Reasoning, . . . . .64 
 
 Fallacy is the more likely to obtain reception, the more it is 
 obscured and disguised by obUquity and complexity of expres- 
 sion, ........ 64 
 
 It is apt, therefore, to slip accidentally from the careless 
 Reasoner, or to be brought forward in that form 
 deliberately by the Sophist, . . . .64 
 
 Reasoning expressed in elliptical language affords opportunity 
 
 for the concealment of Fallacy, . . . .64 
 
 A very Long Discussion is one of the most effectual veils of 
 
 Fallacy, ...... .65 
 
 It is an error to assume, that all Fallacies are easy of Detection, 65 
 
 § VII. — Of Fallacies in Form, .... .65 
 
Xll CONTENTS. 
 
 PAGE 
 
 Fallacies, common in practice, of supposing the Conclusion 
 false, because the Premiss is false, or because the Argu- 
 ment is unsound ; and inferring the truth of the Premiss 
 from that of the Conclusion, . . . . .66 
 
 A weak Argument is always detrimental, . . .66 
 
 Precautions to be taken against fallacious Arguments, 66 
 
 § VIII. — Of Ambiguous Middle, . . . . .66 
 
 Consideration of the semi-logical Fallacy, in which the 
 extremes are compared with two different terms, the middle 
 being used in two different senses in the two Premises. 
 The fallacy of Equivocation, . . . .67 
 
 Fallacia Figurce Dictionis, the Fallacy built on the gram- 
 matical structure of Language, . . . .67 
 
 Paronymous Words, . . . . . . 67 
 
 The fallacy founded on Etymology, viz., when a term is used 
 at one time in its customary, and at another, in its Etymo- 
 logical sense, . .... .68 
 
 § IX. — The Fallacy of Interrogation, — Fallacia Plurium Interroga- 
 
 tionum, ...... . . 69 
 
 § X. — Fallacia Equivocationis, — Equivocation, Ambiguity, . 70 
 
 Words come to have two meanings in various ways : — . 70 
 
 1. By accident: — Strictly Equivocal Words, . . 70 
 
 2. Distinction between the Jirst and second Intention in the 
 
 use of Terms : — 
 The first intention is a Vague and General signification, . 10 
 The second intention, a Precise and Limited (Technical) 
 
 meaning, ....... 70 
 
 3. Two or more Things connected by Resemblance or 
 
 Analogy, have frequently the same name, . .71 
 
 L Proper. — Original or primary meanings of words, . 71 
 2. Improper, — Secondary or transferred meanings, . . 71 
 
 4. Several things are called by the same Name, in consequence 
 
 of being connected by vicinity of Time and Place, . 71 
 
 Under this head come the connection of Cause and Effect, 
 
 or of Part and Whole, &c., . . . .71 
 
 The copiousness and consequent precision of the Greek 
 language exemplified in its distinct terms for expressing 
 an act, an^! the result of that act, . . .72 
 
 The remedy for Ambiguity is a definition of the Term which 
 
 is suspected of being used in two senses, . . .72 
 
 To avoid Fallacy or Vei'bal Controversy, it is only necessary 
 to insist that the term be employed uniformly in the same 
 sense, as far as the existing question is concerned, . 72 
 
 Several Species of Ambiguity arising from the Context, . 73 
 
 The Fallacy of Division, . . . . .73 
 
 The Fallacy of Composition, . . . .73 
 
 Examples: — The Docti-ine of Necessity, . . .73 
 
 The reasoning employed by Adventurers in Lotteries, . 73 
 Infidel arguments on Miracles, . . . .74 
 
 This Fallacy may often be considered as turning on the ambi- 
 guity of the word "all," . . . . .74 
 Fallacious reasoning in respect to Undefined Duties, . . 74 
 Fallacy respecting pi-esumed Incompatibles, . . .74 
 § XI. — Fallacia Accidentis with its converse — Fallacia a dicto secvn- 
 
 dum quid ad dictum simpliciter, . . . . .74 
 
that of 
 
 75 
 75 
 75 
 
 76 
 
 76 
 
 7 
 
 CONTENTS. xiii 
 
 PAGE 
 
 Fallacies arising from the occasional, partial, and temporary 
 variations in the acceptation of particular terms, 
 § XII.- -Non-Logical (OR Material) Fallacies, 
 Begging the Question, (Petitlo principii,) 
 
 Arguing in a Circle, .... 
 
 Example in the science of INIechanics, 
 The English Language very suitable for the Fallacies of 
 Fetitio principii, from its abounding in synonymous expres- 
 sions drawn from two distinct languages, and which have 
 no resemblance in sound, nor connection in etymology, . "6 
 § XIII.— Falsity, or Undue AssmiPTioN of a Fremiss when it is not 
 
 equivalent to, or dependent on, the Conclusion, . .76 
 
 Investigation is a perfectly distinct business from Argumen- 
 tation, ...... 
 
 In philosophical Investigation, it is a necessary caution not 
 to assume one thing to be the cause of another, when 
 perhaps it is only an accidental concomitant. 
 Examples of the undue assumption of Premises, 
 Cause and Eeason confounded together. 
 Indirect Assumption of Premises, . • • _ 
 
 This Fallacy often combined with that of ignoratio clench, 
 
 § XIV.— The Fallacy of Irrelevant Conclusion, commonly called 
 ignoratio elenchi, . . • • • • 
 
 In this fallacy, various kinds of Propositions are, accordmg 
 
 to the occasion, substituted for the one of which proof is 
 
 required, . . • • • 
 
 Examples of this Fallacy, . . • 
 
 Examples of the Combination of this Fallacy with 
 
 Petitio principii, . . . • 
 
 Argumentum ad hominem,^ 
 Argumentum ad verecundiam, 
 Argmentum ad popidum, 
 
 Argumentum ad rem, .... 
 Argumentum ad ignorantiam. 
 Technical Analysis of these Arguments, 
 Use of ambiguous Terms in this Fallacy, 
 
 ^ XV. In Protracted Controversy a party uses the Fallacy of 
 
 Ignoratio elenchi, to Shift his Ground, . • ^ 
 
 A similar practice is that of Combating both your opponent s 
 
 Premises a/^erwa^e/y— shifting from one to the other without 
 
 deciding upon either, . • • ,' , ' ^^ 
 
 Fallacy to the use of which many a guilty person placed on 
 
 trial owes his acquittal, . • ' • .81 
 
 § XVI.— Fallacy of Objections, . • • • * ^'0 
 
 The Universal Fallacy of Infidels, ... 
 
 The Fallacy of Anti-Keformers, 
 § XVIL— The Fallacy of proving or disproving Some Part of that 
 which is rciiuired, suppressing all mention of the rest, . 
 
 Precaution against ever advancing Arguments that cannot be 
 
 well maintained, . . . • • .S3 
 
 § XVIII —Statement of the method of proceeding most conducive to 
 the success of this Fallacy, namely, by peculiar arrangement 
 of the Premises and Arguments, and suppression of the Con- 
 clusion, ...•••• 
 
 77 
 77 
 77 
 77 
 78 
 
 78 
 79 
 
 80 
 80 
 80 
 80 
 80 
 80 
 SO 
 81 
 
 81 
 
 82 
 82 
 
 82 
 
 83 
 
xiV 
 
 CONTENTS. 
 
 § XIX. -Jests ake Fallacies so palpable as not to deceive, yet bearing 
 that resemblance to Argument which is calculated to amuse by 
 the contrast, . , ^ -^ 
 
 CHAPTER VI. 
 
 ESSAY ON THE PROVINCE OF EEASONING. 
 Introduction, .... 
 
 § I. —Of Induction, ... 
 
 The alleged superiority of the Inductive to'the Syllogistic 
 
 method of seeking truth, is a mistake, . 
 The mistake has arisen from applying two diflferent meanings' 
 to the word Induction, which is sometimes employed to 
 designate the Process of Investigation and of Collecting 
 I acts, and sometimes the Deducing of an Inference from 
 those Facts, . . . . 
 
 Induction may be stated syllogistically when it is an argument,' 
 but when it is a process of Inquiry, it is out of the province 
 of Logic, ...... 
 
 Great judgment and caution require to be exercised in the* 
 
 Assuniption of Premises in Induction, 
 The Laying down of Premises requires a competent knowledge * 
 
 of the nature of the subject discussed, 
 The Degree of Evidence for any Proposition to be assumed ' 
 as a Premiss, is a consideration in the province of the 
 Science that furnishes the subject matter of the Argument, 
 The Rules of Logic have nothing to do with the Truth or 
 Falsity of the Premises, but merely teach us to decide 
 whether the Conclusion follows fairly from the Premises 
 or not, ...... 
 
 Investigation. The Inductive Process, 
 In Induction, the more doubtful of the two Premises is usually 
 suppressed, ...... 
 
 Difference between Induction and Example, . 
 § n. — On the Discovert or Truth, .... 
 
 Consideration of the question, whether New Truths are 
 
 brought to light merely by a process of Reasoning, 
 This question decided negativ^ely. 
 The objection to the syllogism urged by Professor Campbell 
 
 on this ground, 
 Refutation of that Objection, ...*.' 
 Difficulty of bringing before the Mind the several bearings,— 
 
 the various applications,— of any one Proposition, . 
 Comprehensiveness of Terms. Division and Generalization 
 
 m a great degree arbitrary. Consequences, 
 The Ten Categories or Predicaments of Aristotle and other 
 Logical writers. Their use, .... 
 
 Double Meanings of the terms Discovery and New Truths :— 
 1st kind. Such Truths as were, before they were discovered, 
 absolutely unknown ; matters of fact, &c. These truths 
 are gained from observation and testimony, and are 
 commonly called Information, .... 
 
 2d kind. Discoveries elicited by Reasoning, and implied in 
 that which we already know ; not taken upon trust, nor 
 ascertained by observation. These are called Instruction, 
 
 83 
 
 85 
 
 85 
 
 85 
 
 86 
 
 86 
 
 87 
 87 
 
 87 
 
 87 
 87 
 
 88 
 88 
 
 88 
 88 
 
 89 
 89 
 
 89 
 
 89 
 
 90 
 90 
 
 90 
 
 90 
 
CONTENTS. XV 
 
 PAGE 
 
 Plato's Theory of Ideas, . . . . .91 
 
 Mathematical Propositions are not properly True or False in 
 the same sense as any Proposition respecting real fact is 
 so called, . . . . . , .91 
 
 Ethical Propositions, . . . . . .91 
 
 Importance of distinguishing the two kinds of Discovery of 
 
 Truth, Information and Instruction, . . .92 
 
 Employment of Eeasoning in the establishment of Matters 
 
 of Fact. Physical Discoveries, . . . .93 
 
 Importance of ascertaining and keeping in mind the Degree 
 of Evidence for the Facts which are to be used as Data, 
 since, otherwise, the Conclusions could not be relied on, 
 however accurate the Eeasoning, . . . .93 
 
 Individual Facts may be elicited by skilfully combining, and 
 
 Reasoning from. Facts already known, . . .93 
 
 General Facts established by Reasoning from Induction, . 93 
 
 Illustrated by Examples, . . . . ,93 
 
 These operations distinct from Reasoning, . . .94 
 
 Physical Discoveries compared with Logical Discoveries, . 94 
 The same Discovery may be of the nature of a Logical Dis- 
 covery to one man, and a Physical Discovery to another, 94 
 Scientific Truths, . . . . . .95 
 
 Mathematical Definitions cannot properly be called true or 
 
 false, . . . . . . .95 
 
 Nominal and Real Definitions, . . . .96 
 
 The question considered, whether such great Discoveries as 
 have been made in Natural Philosophy, can be accomplished 
 by Reasoning, . . . . . .96 
 
 The word Reasoning used in this case ambiguously, , 96 
 
 The question may be answered afiirmatively in one sense, and 
 
 negatively in another, . . . . .96 
 
 The two senses in which the word Reasoning is used, are 
 
 perpetually confounded together, . . . . 96 
 
 The Discoveries of General Laws of Nature, &c. are New 
 
 Truths in Different Senses to Different Persons, . . 97 
 
 Particular Facts, the immediate result of observation and 
 experiment, are frequently uninteresting and insignificant, 
 till so combined as to lead to a grand general result, . 97 
 
 The skilful selection and combination of Truths, long and 
 generally known, so as to elicit important and hitherto 
 unthought of Conclusions, shows a Master Mind, . .98 
 
 Mathematical Discoveries always of the nature of Logical 
 
 Discoveries, . . . . . .98 
 
 The Operations strictly comprehended under the word 
 "Reasoning" are not alone sufficient for Logical and 
 Physical Discoveries, . . . . .98 
 
 In Logical Discoveries, is required a skilful Selection and 
 
 Combination of known Truths, . . . .98 
 
 In Physical Discoveries, we must employ, generally in addition 
 
 to the former, the operations of Observation and Experiment, 98 
 In the study of Nature, both kinds of Investigation are uuited, 99 
 In Mathematics, and in most discussions relating to Ethics and 
 
 Jurisprudence, we employ only Logical Investigation, . 99 
 Mathematical Reasoning compared with Reasonings which 
 
 regard matters of fact, . . . . .99 
 
XVI CONTENTS. 
 
 PAGE 
 
 §111 Of Inference AND Proof, ..... 100 
 
 Proving defined, the assigning of a Keason or Argument for 
 
 the support of a 5'zve?i Proposition, . . .101 
 
 Inferring defined, the deduction of a Conclusion from given 
 
 Premises, ... ... 101 
 
 The Philosopher i?i/ers; the Advocate p'ores, . . 101 
 
 These processes arise from, and generate, very diiferent Habits 
 of Mind, and require a very different kind of Training and 
 Precept, . . . . . , .102 
 
 The Lawyer, Controversialist, or Rhetorician, who is, in his 
 own province, the most skilful, may be but ill-fitted for 
 philosophical investigation, . . . .102 
 
 The ablest Philosopher may make an indifferent disputant, 102 
 It is of importance to comprehend this distinction, as it is a 
 common fault to forget the Philosopher or Theologian, and 
 to assume the Advocate, . . . . .102 
 
 The bare process of Reasoning is the same in both cases, but 
 not so the preparatory processes requisite in order to 
 employ Reasoning profitably, .... 102 
 
 The Aristotelian and Baconian Logic, . . . 103 
 
 The Fitness of Logic for Academical Education, . . 103 
 
 § IV. — Of Verbal and Real Questions, .... 104 
 
 A Verbal Question distinguished from a Real Question, . 104 
 
 A Verbal Question is one in which the parties employ the 
 
 same Terms in different senses, . . . .104 
 
 A Real Question is one in which the parties differ as to the 
 
 Opinions they hold of the Things in question, . .104 
 
 When Verbal questions are mistaken for Real, much con- 
 fusion of thought and unprofitable Avrangling, — Logomachy 
 (dispute about words), — will be generally the result, . 105 
 
 Real questions not to be stigmatised as Verbal controversies, 106 
 
 § v.— Op Realism, . . . . . . .106 
 
 Erroneous notion of the Realists, that Genus and Species are 
 Real Things, existing independently of our conceptions and 
 expressions, . . . . . .106 
 
 That notion sustained by the transferred and secondary use 
 
 of the words same^ one and the same, identical., &c. . . 106 
 
 A mass of confused Reasoning and Logomachy may be cleared 
 away by attending to the proper use of such ambiguous 
 terms, ...... 
 
 Index, 
 
 107 
 109 
 
LOGIC. 
 
 INTRODUCTORY SECTION. 
 
 Logic, in the most extensive sense whicli it can with propriety be 
 made to bear, may be considered as the Science and also as the Art 
 of Reasoning. It investigates the principles on which argumentation 
 is conducted, and furnishes rules to secure the mind from error in its 
 deductions. Its most appropriate office, however, is that of instituting 
 an analysis of the process of the mind in Reasoning: and in this 
 point of view it is, as has been stated, strictly a Science : while con- 
 sidered in reference to the practical rules above mentioned, it may be 
 called the Art of Reasoning. This distinction, as will hereafter 
 appear, has been overlooked, or not clearly pointed out by most 
 writers on the subject. Logic having been in general regarded as 
 merely an Art ; and its claim to hold a place among the Sciences 
 having been expressly denied. 
 
 Considering how early Logic attracted the attention of philoso- 
 phers, it may appear surprising that so little progress should have 
 been made, as is confessedly the case, in developing its principles, 
 and perfecting the detail of the system: and this circumstance has 
 been brought forward as a proof of the barrenness and futility of the 
 study. But a similar argument might have been urged with no 
 less plausibility, in past ages, against the study of Natural Philo- 
 sophy, and very recently against that of Chemistry. No Science can 
 be expected to make any considerable progress, which is not culti- 
 vated on right principles. Whatever may be the inherent vigour of 
 the plant, it will neither be flourishing nor fruitful till it meet with a 
 suitable soil and culture: and in no case is the remark more appli- 
 cable than in the present ; the greatest mistakes having always pre- 
 vailed respecting the nature of Logic, and its province having in con- 
 sequence been extended by many writers to subjects with which it 
 has no proper connection. Indeed, with the exception of Aristotle, 
 (who is himself not entirely exempt from the errors in question,) 
 liardly a writer on Logic can be mentioned who has clearly perceived, 
 and steadily kept in view throughout, its real nature and object. 
 Before his time, no distinction was drawn between the Science of which 
 we are speaking, and that which is now usually called Metaphysics : 
 a circumstance which alone shows how small was the progress made 
 in earlier times. Indeed those who first turned their attention to tlie 
 
 u 
 
jd INTRODUCTION. 
 
 subject, hardly thought of inquinng into the process of Reason itself, 
 but confined themselves almost entirely to certain preliminary points, 
 the discussion of which is (if logically considered) subordinate to that 
 of the main inquiry. 
 
 Zeno the Eleatic, whom most accounts represent as the earliest 
 systematic writer on the subject of Logic, or as it was then called, 
 Dialectics, divided his work into three parts ; the first of which (upon 
 Consequences) is censured by Socrates [Plato, Parmen.] for obscurity 
 and confusion. In his second part, however, he furnished that inter- 
 rogatory method of disputation [^k^urwii] which Socrates adopted, and 
 which has since borne his name. The third part of his work was 
 devoted to what may not improperly be termed the art of wrangling, 
 [g^/ffr/;^!?] which supplied the disputant with a collection of sophistical 
 questions, so contrived that the concession of some point which 
 seemed unavoidable, immediately involved some glaring absurdity. 
 This, if it is to be esteemed as at all falling within the province of 
 Logic, is certainly not to be regarded (as some have ignorantly or 
 heedlessly represented it) as its principal or proper business. The 
 Greek philosophers generally have unfortunately devoted too much 
 attention to it : but we must beware of falling into the vulgar error of 
 supposing the ancients to have regarded as a serious and intrinsically 
 important study, that which in fact they considered as an ingenious 
 recreation. The disputants diverted themselves in their leisure 
 hours by making trial of their own and their adversary's acuteness, 
 in the endeavour mutually to perplex each other with subtle fallacies ; 
 much in the same way as men amuse themselves with propounding 
 and guessing riddles, or with the game of chess ; to each of which 
 diversions the sportive disputations of the Ancients bore much resem- 
 blance. They M^ere closely analogous to the wrestling and other 
 exercises of the gymnasium, these last being reckoned conducive to 
 bodily vigour and activity, as the former were to habits of intellectual 
 acuteness ; but the immediate object in each was a sportive, not a 
 serious contest ; though, doubtless, fashion and emulation often 
 occasioned an undue importance to be attached to success in each. 
 
 Zeno then is hardly to be regarded as any further a logician than 
 as to what respects his erotetic method of disputation ; a course of 
 argument constructed on this principle being properly an hypothetical 
 sorites, which may easily be reduced into a series of syllogisms. 
 
 To Zeno succeeded Euclid of Megara, and Antisthenes, both pupils 
 of Socrates. The former of these prosecuted the subject of the third 
 part of his predecessor's treatise, and is said to have been the author of 
 many of the fallacies attributed to the Stoical school. Of the writings 
 of the latter, nothing certain is known : if, however, we suppose the 
 above mentioned sect to be his disciples in this study, and to have 
 retained his principles, he certainly took a more correct view of the 
 su])ject than Euclid. The Stoics divided all Asxrat, every thing that 
 
I?^TRODUCTION. 3 
 
 could be said, into three classes : 1st, the simple term ; 2d, the pro- 
 position ; 3d, the syllogism ; viz. the hijpothetical ; for thcj seem to 
 have had little notion of a more rigorous analysis of argument than 
 into that familiar form. 
 
 We must not here omit to notice the merits of Archytus, to whom 
 we are indebted for the doctrine of the categories. He, however, (as 
 well as the other writers on the subject,) appears to have had no 
 distinct view of the proper object and just limits of the science of 
 Logic ; but to have blended with it ]\Ietaphysical discussions not 
 strictly connected with it, and to have dwelt on the investigation of 
 the nature of terms and propositions, without maintaining a constant 
 reference to the principles of Reasoning, to which all the rest should 
 be made subservient. 
 
 The state then in which Aristotle found the Science, (if indeed it 
 can properly be said to have existed at all before his time,) appears 
 to have been nearly this : the division into simple terms, propositions 
 and syllogisms, had been slightly sketched out ; the doctrine of the 
 categories, and perhaps that of the opposition of propositions, had 
 been laid down ; and, as some believe, the analysis of species into 
 genus and differentia, had been introduced by Socrates. These, at 
 best, were rather the materials of the system, than the system itself ; 
 the foundation of which, indeed, he distinctly claims the merit of 
 having laid ; and which remains fundamentally the same as he left it. 
 
 It has been remarked that the Logical system is one of those few 
 theories which have been begun and perfected by the same individual. 
 The history of its discovery, as far as the main principles of the 
 science are concerned, properly commences and ends with Aristotle. 
 And this may perhaps in part account for the subsequent perversions 
 of it. The breA^ty and simplicity of its fundamental truths, (to wliich 
 indeed all real science is perpetually tending,) has prol)ably led many 
 to suppose that something much more complex, abstruse, and mys- 
 terious, remained to be discovered. The vanity by which all men are 
 prompted unduly to magnify their own pursuits, has led unphiloso- 
 phical minds, not in this case alone, but in many others, to extend 
 the boundaries of their respective Sciences, not by the patient develop- 
 ment and just application of the principles of those Sciences, but 
 by wandering into irrelevant subjects. The mystical cmph)yment of 
 numbers by Pythagoras, in matters utterly foreign to x\rithmetic, is 
 perhaps the earliest instance of the kind. A more curious and impor- 
 tant one is the degeneracy of Astronomy into judicial Astrology ; but 
 none is more striking tlian the misapplication of Logic, by those who 
 have treated of it as ** the art of rightly employing the rational 
 faculties," or who have intruded it into the province of Natural 
 Philosophy, and regarded the syllogism as an engine f<jr the investi- 
 gation of nature : overlooking the boundless field that was before 
 them within the legitimate limits of the Science ; and not perceiving 
 
4 INTRODUCTION. 
 
 the importance and difficulty of the task of completing and properly 
 tilling up the masterly sketch before them. 
 
 The writings of Aristotle were not only absolutely lost to the world 
 for about two centuries, but seem to have been but little studied for 
 a long time after their recovery. An Art, however, of Logic, derived 
 from the principles traditionally preserved by his disciples, seems to 
 have been generally known, and was employed by Cicero in his 
 philosophical works ; but the pursuit of the science seems to have 
 been abandoned for a long time. Early in the Christian era, the 
 Peripatetic doctrines experienced a considerable re^dval ; and we meet 
 with the names of Galen and Porphyry as Logicians : but it is not till 
 the fifth century that Aristotle's Logical works were translated into 
 Latin by the celebrated Boethius. Not one of these seems to have 
 made any considerable advances in developing the Theory of Reason- 
 ing. Of Galen's labours little is known; and Porphyry's principal 
 work is merely on the p^edicables. We have little of the Science 
 till the revival of learning among the Arabians, by whom Aristotle's 
 treatises on this as well as on other subjects were eagerly studied. 
 
 Passing by the names of some Byzantine writers of no great impor- 
 tance, we come to the times of the Schoolmen, whose waste of ingenuity 
 and frivolous subtilty of disputation need not be enlarged upon. It 
 may be sufficient to observe, that their fault did not lie in their diligent 
 study of Logic, and the high value they set upon it, but in their 
 utterly mistaking the true nature and object of the science ; and by 
 attempting to employ it for the purpose of physical discoveries, 
 involving every subject in a mist of words, to the exclusion of sound 
 philosophical investigation. Their errors may serve to account for 
 the strong terms in which Bacon sometimes appears to censure 
 JiOgical pursuits ; but that this censure was intended to bear against 
 the extravagant perversions, not the legitimate cultivation of the 
 Science, may be proved from his own observations on the subject, in 
 his Advancement of Learning. 
 
 His moderation, however, was not imitated in other quarters. 
 Even Locke confounds in one sweeping censure the Aristotelic 
 theory, with the absurd misapplications and perversions of it in later 
 years. His objection to the Science, as unserviceable in the dis- 
 covery of truth, (which has of late been often repeated) while it holds 
 good in reference to many (misnamed) Logicians, indicates that with 
 regard to the true nature of the science itself, he had no clearer 
 notions than they have, of the proper province of Logic, viz. Reason- 
 ing ; and of the distinct character of that operation from the observa- 
 tions and experiments which are essential to the study of nature. 
 
 An error apparently different, but substantially the same, pervades 
 the treatises of Watts and other modern writers on the subject. 
 Perceiving the inadequacy of the syllogistic theory to the vast pur- 
 poses to which others had attempted to apply it, he still craved after 
 
INTRODUCTION. 5 
 
 the attainment of some equally comprehensive and all-powerful 
 system ; which he accordingly attempted to construct, under the title 
 of The Right Use of Reason; which was to he a method of invigorat- 
 ing and properly directing all the powers of the mind : a most mag- 
 nificent object indeed, but one which not only does not fall under the 
 province of Logic, but cannot be accomplished by any one Science or 
 System that can even be conceived to exist. The attempt to com- 
 prehend so wide a field is no extension of Science, but a mere verbal 
 generalization, which leads only to vague and barren declamation. 
 In every pursuit, the more precise and definite our object, the more 
 likely we are to attain some valuable result ; if, like the Platonists, 
 who sought after the uvTuyadov, the abstract idea of good, we pursue 
 some specious but ill-defined scheme of universal knowledge, we shall 
 lose the substance while gi'asping at a shadow, and bewilder our- 
 selves in empty generalities. 
 
 It is not perhaps much to be wondered at, that in still later times 
 several ingenious writers, forming their notions of the Science itself 
 from professed masters in it, such as have just been alluded to, and 
 judging of its value from their failures, should have treated the Aris- 
 totelic system with so much reprobation and scorn. Too much pre- 
 judiced to bestow on it the requisite attention for enabling them clearly 
 to understand its real character and object, or even to judge correctly 
 from the little they did understand, they have assailed the study with 
 a host of objections, so totally irrelevant, and consequently impotent, 
 that, considering the talents and general information of those from 
 whom they 2)roceed, they might excite astonishment in any one who 
 did not fully estimate the force of very early prejudice. 
 
 Logic has usually been considered by these objectors as professing 
 to furnish a peculiar method of Reasoning, instead of a metliod of 
 analyzing that mental process which must invariably take place in all 
 correct Reasoning ; and accordingly they have contrasted the ordinary 
 mode of reasoning with the syllogistic ; and have brought forward with 
 an air of triumph the argumentative skill of many who never learned 
 the system : a mistake no less gross than if any one shoidd regard 
 Grammar as a peculiar language, and contend against its utility on 
 the ground that many speak correctly who never studied the principles 
 of Grammar; whereas Logic, which is, as it were, the Grammar of 
 Reasoning, does not bring forward the regular syllogism as a distinct 
 mode of argumentation, designed to be substituted for any other mode ; 
 but as the form to wliicli all correct Reasoning may be ultimately 
 reduced, and which consequently serves the purpose (when we are 
 employing Logic as an Art) of a test to try the validity of any argu- 
 ment, in the same manner as by chemical analysis we dcvelo]) and 
 submit to a distinct examination the elements of wliich any compound 
 body is composed, and are thus enabled to detect any latent soj)liisti- 
 cation and impurity. 
 
b INTRODUCTION. 
 
 Complaints have also been made that Logic leaves untouched the 
 greatest difficulties, and those which are the sources of the chief 
 errors in Reasoning ; viz. the ambiguity or indistinctness of terms, 
 and the doubts respecting the degrees of evidence in various proposi- 
 tions: an objection which is not to be removed by any such attempt 
 as that of Watts to lay down " rules for forming clear ideas, and for 
 guiding the judgment ;" but by replying that no Art is to be censured 
 for not teaching more than falls within its province, and indeed more 
 than can be taught by any conceivable art. Such a system of 
 universal knowledge as should instruct us in the full meaning of every 
 term, and the truth or falsity, certainty or uncertainty, of every pro- 
 position, thus superseding all other studies, it is most unphilosophical 
 to expect or even to imagine. And to find fault with Logic for not 
 performing this, is as if one should object to the Science of Optics for 
 not giving sight to the blind ; or as if (like the man of whom War- 
 burton tells a story in his Div. Leg.) one should complain of a reading 
 glass for being of no service to a person who had never learned to 
 read. 
 
 In fact, the difficulties and errors above alluded to are not in the 
 process of Reasoning itself, (which alone is the appropriate province 
 of Logic,) but in the subject matter about which it is employed. 
 This process will have been correctly conducted if it have conformed 
 to the Logical rules which preclude the possibihty of any error creeping 
 in between the principles from which we are arguing, and the conclu- 
 sions we deduce from them. But still that conclusion may be false, 
 if the princijjles we start from are so. In like manner, no Arithmetical 
 skill will secure a correct result to a calculation, unless the data are 
 correct from which we calculate ; nor does any one on that account 
 undervalue Arithmetic ; and yet the objection against Logic rests on 
 no better foundation. 
 
 There is in fact a striking analogy in this respect between the two 
 Sciences. All numbers (w^hich are the subject of Arithmetic) must 
 be numbers of some things, whether coins, persons, measures, or any 
 thing else ; but to introduce into the Science any notice of the things 
 respecting which calculations are made, would be evidently irrelevant, 
 and would destroy its scientific characters : we proceed therefore with 
 arbitrary signs representing numbers in the abstract. So also does 
 Logic pronounce on the validity of a regularly constructed argument 
 equally well, though arbitrary symbols may have been substituted for 
 the terms, and consequently without any regard to the things signified 
 by those terms. And the probability of doing this (though the 
 employment of such arbitrary symbols has been absurdly objected to, 
 even by writers who understood not only Arithmetic but Algebra) is 
 a proof of the strictly scientific character of the system. But many 
 professed Logical writers, not attending to the circuniiStances which 
 have been just mentioned, have wandered into disquisitions on various 
 
INTRODUCTION. 7 
 
 branches of knowledge; disquisitions which must evidently be as 
 boundless as human knowledge itself, since there is no subject on 
 which Reasoning is not employed, and to which consequently Logic 
 may not be ajJjMed. The error lies in regarding every thing as the 
 proper 2Jromnce of Logic, to which it is ajyplicabk. A similar error 
 is complained of by Aristotle, as having taken place with respect to 
 Rhetoric; of which indeed we find specimens in tlie arguments of 
 several of the interlocutors in Cic. de Orator e. 
 
 From what has been said, it will be evident that there is hardly any 
 subject to which it is so difiicult to introduce the student in a clear 
 and satisfactory manner, as the one we are now engaged in. In any 
 other branch of knowledge, the reader, if he have any previous 
 acquaintance with the subject, will usually be so far the better pre- 
 pared for comprehending the exposition of the principles ; or if he be 
 entirely a stranger to it, will at least come to the study with a mind 
 imbiassed, and free from prejudices and misconceptions ; whereas in 
 the present case it cannot but happen that many who have given some 
 attention to Logical pursuits, (or what are usually considered as such) 
 will frequently have rather been bewildered by fundamentally erro- 
 neous views, than prepared by the acquisition of just principles for 
 ulterior progress ; and that not a few who pretend not to any acquain- 
 tance whatever with the Science, will yet have imbibed either such 
 prejudices against it, or such false notions respecting its nature, as 
 cannot but prove obstacles in their study of it. 
 
 There is, however, a difficvdty which exists more or less in all 
 abstract pursuits, though it is perhaps more felt in this, and often 
 occasions it to be rejected by beginners as dry and tedious ; viz. the 
 difiiculty of perceiving to what ultimate end, — to what practical or 
 interesting application the abstract principles lead which are first laid 
 before the student ; so that he will often have to work his way 
 patiently through the most laborious part of the system before he can 
 gain any clear idea of the drift and intention of it. 
 
 This complaint has often been made by chemical students, who are 
 wearied with descriptions of oxygen, hydrogen, and other invisible 
 elements, before they have any knowledge respecting sucli bodies as 
 commonly present themselves to the senses. And accordingly some 
 teachers of Chemistry obviate in a great degree this objection, by 
 adopting the analytical instead of the synthetical mode of procedure, 
 when they are first introducing the subject to beginners ; i.e. instead 
 of synthetically enumerating the elementary substances, proceeding 
 next to the simplest combinations of these, and concluding with those 
 more complex substances wliich are of the most common occurrence, 
 they begin by analyzing these last, and resolving them step by step 
 into their simple elements; thus presenting the subject at once in an 
 interesting point of view, and clearly setting fortli the object of it. 
 The synthetical form of teaching is indeed sufficiently interesting to 
 
8 INTRODUCTION. 
 
 one who has made considerable progress in any study ; and being 
 more concise, regular, and systematic, is the form in which our know- 
 ledge naturally arranges itself in the mind, and is retained by the 
 memory : but the analytical is the more interesting, easy, and natural 
 kind of introduction, as being the form in which the first invention or 
 discovery of any kind of system must originally have taken place. 
 
 It may be advisable, therefore, to begin by giving a slight sketch, 
 in this form, of the Logical system, before we enter regularly upon 
 the details of it. The reader will thus be presented with a kind of 
 imag-inary history of the course of inquiry by which the Logical system 
 may be conceived to have occurred to a philosophical mind. 
 
 In every instance in which we reason, in the strict sense of the 
 word, i.e. make use of arguments, whether for the sake of refuting an 
 adversary, or of conveying instruction, or of satisfying our own minds 
 on any point, whatever may be the subject we are engaged on, a 
 certain process takes place in the mind, which is one and the same in 
 all cases, provided it be correctly conducted. 
 
 Of course it cannot be supposed that every one is even conscious of 
 this process in his own mind, much less is competent to explain the 
 principles on which it proceeds ; which indeed is, and cannot but be, 
 the case with every other process respecting which any system has 
 been formed ; the practice not only may exist independently of the 
 theory, but must have preceded the theory ; there must have been 
 language before a system of Grammar could be devised ; and musical 
 compositions previous to the science of Music. This by the way will 
 serve to expose the futility of the popular objection against Logic, that 
 men may reason very well who know nothing of it. The parallel 
 instance adduced, shows that such an objection might be applied in 
 many other cases, Avhere its absurdity would be obvious ; and that 
 there is no reason for deciding thence, either that the system has no 
 tendency to improve practice, or that even if it had not, it might not 
 still be a dignified and interesting pursuit. 
 
 One of the chief impediments to the attainment of a just view of 
 the nature and object of Logic, is the not fully understanding, or not 
 sufficiently keeping in mind, the sameness of the Reasoning process 
 in all cases ; if, as the ordinary mode of speaking would seem to 
 indicate. Mathematical Reasoning, and Theological, and Metaphysical, 
 and Political, &c., were essentially different from each other, i.e. 
 difierent kinds of reasoning, it would follow, that supposing there could 
 be at all any such Science as we have described Logic, there must 
 be so many difierent species, or at least different branches of Logic. 
 And such is perhaps the most prevailing notion. Nor is this much to 
 be wondered at ; since it is evident to ail that some men converse and 
 write in an argumentative wajt, very justly on one subject, and very 
 erroneously on another, in which again others excel, who fail in the 
 former. This error may be at once illustrated and removed, by con- 
 
INTRODUCTION. 9 
 
 sidering the parallel instance of Arithmetic, in which every one is 
 aware that the process of a calculation is not affected hy the nature 
 of the objects whose numbers are before us: but that {e.g.) the 
 multiplication of a number is the very same operation, whether it be 
 a number of men, of miles, or of pounds ; though nevertheless men 
 may perhaps be found who are accurate in calculations relative to 
 Natural Philosophy, and incorrect in those of Political Economy, from 
 their different degrees of skill in the subjects of these two Sciences ; 
 not surely because there are dilierent arts of Arithmetic applicable to 
 each of these respectively. 
 
 Others again, who are aware that the simple system of Logic may 
 be applied to all subjects whatever, are yet disposed to view it as a 
 pecuhar method of Reasoning, and not as it is, a method of unfolding 
 and analyzing our Reasoning : whence many have been led {e.g. the 
 author of the Philosophy of Rhetoric) to talk of comparing syllogistic 
 Reasonino- with moral Reasonino- and to take it for g^ranted that it is 
 possible to reason correctly without reasoning Logically ; which is in 
 fact as great a blunder as if any one were to mistake Grammar for a 
 peculiar language, and to suppose it possible to speak correctly with- 
 out speaking Grammatically. They have in short considered Logic 
 as an Art of Reasoning ; whereas, so far as it is an Art, it is the Art 
 of Reasoning: the Logician's object being, not to lay down principles 
 by which one may reason, but by which all must reason, even though 
 they are not distinctly aware of them : to lay doAvn rules, not which 
 maybe followed with advantage, but which cannot possildy be departed 
 from in sound reasoning. These misapprehensions and objections 
 being such as lie on the very threshold of the subject, it would have 
 been hardly possible, without noticing them, to convey any just notion 
 of the nature and design of the Logical system. 
 
 Supposing it then to have been perceived that the operation of 
 Reasoning is in all cases the same, tlie analysis of that operation could 
 not fail to strike the mind as an interesting matter of inquiry : and 
 moreover, since (apparent) arguments which arc unsound and incon- 
 clusive, are so often employed either yVom error or from design; and 
 even those who are not misled by these fallacies, are so often at a loss 
 to detect and expose them in a manner satisfactory to others, or even 
 to themselves, it could not but appear desirable to lay down some 
 general rules of Reasoning, applicable to all cases, by which a person 
 might be enabled the more readily and clearly to state the grounds of 
 his own conviction, or of his objection to the arguments of an opponent, 
 instead of arguing at random without any fixed and acknowledged 
 principles to guide his procedure. Such rules would be analogous to 
 those of Arithmetic, which obviate the tediousncss and uncertainty of 
 calculations in the head, wherein, after nauch labour, different persons 
 might arrive at different results, without any of them being able dis- 
 tinctly to point out the error of the rest. A system of such rules, it 
 
10 INTRODUCTION. 
 
 is obvious, must, instead of deserving to be called the Art of wrangling, 
 be more justly characterised as *' the Art of cutting short wrangling," 
 by bringing the parties to issue at once, if not to agreement, and thus 
 savuig a waste of ingenuity. 
 
 In pursuing the supposed investigation, it will be found that CA^ery 
 conclusion is deduced, in reality, from two other propositions, (thence 
 called premises ;) for though one of these may be, and commonly is, 
 suppressed, it must nevertheless be miderstood as admitted ; as may 
 easily be made evident by supposing the denial of the suppressed 
 premiss, which will at once invalidate the argument : e.g. if any one 
 from perceiving that the world exhibits marks of design, infers that 
 "it must have had an intelligent author," though he may not be 
 aware in his own mind of the existence of any other premiss, he will 
 readily understand, if it be denied that "whatever exhibits marks of 
 desi.Q-n must have had an intellio-ent author," that the affirmative of 
 that proposition is necessary to the validity of the argument. An 
 argument thus stated regularly and at full length is called a Syllo- 
 gism ; which, therefore, is evidently not a peculiar hind of argument, 
 but only a peculiar ybrwz of expression, in which every argument may 
 be stated. When one of the premises is suppressed, (which for 
 brevity's sake it usually is,) the argument is called an Enthymeme. 
 And it may be worth while to remark, that when the argument is in 
 this state, the objections of an opponent are (or rather appear to be) 
 of tAvo kinds ; viz. either objections to the assertion itself, or objections 
 to its force as an argument ; e.g. in the above instance, an atheist may 
 be conceived either denying that the Avorld does exhibit marks of 
 design, or denying that it follows from thence that it had an intelli- 
 gent author. The only difference in the two cases is, that in the one 
 the expressed premiss is denied, in the other the suppressed; for the 
 force as an argument of either premiss depends on the other premiss : 
 if both be admitted, the conclusion legitimately connected with them 
 cannot be denied. 
 
 It is evidently immaterial to the argument whether the conclusion 
 be placed first or last ; but it maybe proper to remark, that a premiss 
 placed after its conclusion is called the reason of it, and is introduced 
 by one of those conjunctions which are called causal; viz. "since," 
 "because," &c. which may indeed be employed to designate a pre- 
 miss, whether it came first or last; the illative conjunctions, "there- 
 fore," <fec. designate the conclusion. It is a circumstance which often 
 occasions error and perplexity, that both these classes of conjunctions 
 have also another signification, being employed to denote, respectively, 
 cause and eff'ect, as well as premiss and conclusion : e.g. if I say, (to 
 use an instance employed by Aristotle,) "yonder is a fixed star, 
 because it twinkles," or, "it twinkles, and therefore is a fixed star," 
 I employ these conjunctions to denote the connection of premiss and 
 conclusion ; for it is plain that the tAvinkling of the star is not the 
 
INTRODUCTION. 11 
 
 cause of its being fixed, but only the cause of my knowing that it is 
 so: but if I say, " it twinkles because it is a fixed star," or *' it is a 
 fixed star, and therefore twinkles," I am using the same conjunctions 
 to denote the connection of cause and effect ; for in this case the 
 twinkling of the star, being evident to the eye, would hardly need to 
 be proved, but might need to be accounted for. There are, however, 
 many cases in which the cause is employed to prove the existence of 
 its efi^ect ; especially in arguments relating io future events: the cause 
 and the reason, hi that case, coincide ; and this contributes to their being 
 so often confounded together in other cases. In an argument, such 
 as the example above given, it is, as has been said, impossible for any 
 one, who admits both premises, to avoid admitting the conclusion ; 
 but there will be frequently an apparent connection of premises with 
 a conclusion which does not in reality follow from them, though to the 
 inattentive or unskilful the argument may appear to be valid : and 
 there are many other cases in which a doubt may exist whether the 
 argument be valid or not ; i.e. whether it be possible or not to admit 
 the premises, and yet deny the conclusion. It is of the highest im- 
 portance, therefore, to lay down some regular form to which every 
 valid argument may be reduced, and to devise a rule which shall prove 
 the validity of every argument in that form, and consequently the 
 unsoundness of any apparent argument which cannot be reduced to it : 
 e.g. if such an argument as this be proposed, "every rational agent 
 is accountable ; brutes are not rational agents ; therefore they are not 
 accountable:" or aa'ain, "all wise leo-islators suit their laws to the 
 genius of their natio-n ; Solon did this ; therefore he was a wise legis- 
 lator;" there are some, perhaps, who would not perceive any fallacy 
 in such arguments, especially if enveloped in a cloud of words ; and 
 still more when the conclusion is true, or, which comes to the same 
 point, if they are disposed to believe it ; and others might perceive 
 indeed, but might be at a loss to explain the fallacy. Now these 
 (apparent) arguments exactly correspond respectively with the follow- 
 ing, the absurdity of the conclusions from which is manifest: "every 
 horse is an animal ; sheep are not horses ; therefore they are not 
 animals:" and, " all vegetables grow ; an animal grows ; therefore it 
 is a vegetable." These last examples, it has been said, correspond 
 exactly (considered as arguments) with the former ; the question 
 respecting the validity of an argument being, not whether the conclu- 
 sion be true, but whether it follows from the premises adduced. This 
 mode of exposing a fallacy, by bringing forward a similar one whose 
 conclusion is obviously absurd, is often, and very advantageously, 
 resorted to in addressing those who are ignorant of Logical rules ; but 
 to lay down such rules, and cmplt)y them as a test, is evidently a 
 safer and more compendious, as well as a more philoso])hical mode of 
 proceeding. To attain these, it would plainly be necessary to analyze 
 some clear and valid arguments, and to observe in what their conclu- 
 
12 INTRODUCTION. 
 
 siveness consists. Let us suppose, then, such an examination to he 
 made of tlie syllogism above mentioned: " whatever exhibits marks of 
 design had an intelligent author." 
 
 The world exhibits marks of design ; therefore the world had an 
 intellio-ent author. In the first of these premises we find it assumed 
 universally of the class of "things which exhibit marks of design," 
 that they had an intelligent author; and in the other premiss, "the 
 world" is referred to that class as comprehended in it: now it is 
 evident, that Avhatever is said of the whole of a class, may be said of 
 any thing comprehended in that class ; so that we are thus authorized 
 to say of the world, that it had an intelligent author. Again, if we 
 examine a syllogism with a negative conclusion, as, e.g. " nothing 
 which exhibits marks of design could have been produced by chance : 
 the world exhibits, <fec. ; therefore the world could not have been pro- 
 duced by chance." The process of Reasoning will be found to be the 
 same ; since it is evident, that whatever is denied universally of any 
 class, may be denied of any thing that is comprehended in that class. 
 
 On further examination it will be found, that all valid arguments 
 whatever may be easily reduced to such a form as that of the fore- 
 g6ing sj'-llogisms ; and that consequently the principle on which they 
 are constructed is the universal principle of Reasoning. So elliptical 
 indeed is the ordinary mode of expression, even of those who are 
 considered as prolix writers, i.e. so much is implied and left to be 
 understood in the course of argument, in comparison of what is actually 
 stated, (most men being impatient, even to excess, of any appearance 
 of unnecessary and tedious formality of statement,) that a single 
 sentence will often be found, though perhaps considered as a single 
 argument, to contain, compressed into a short compass, a chain of 
 several distinct arguments ; but if each of these be fully developed, 
 and the whole of Avliat the author intended to imply be stated expressly, 
 it will be found that all the steps even of the longest and most com- 
 plex train of Reasoning, may be reduced into the above form. 
 
 It is a mistake (which might appear scarcely worthy of notice had 
 not so many, even esteemed writers, fallen into it) to imagine that 
 Aristotle and other Logicians meant to propose that this prolix form 
 of unfolding arguments should universally supersede, in argumentative 
 discourses, the common forms of expression ; and that to reason 
 Logically, means, to state all arguments at full length in the syllogis- 
 tic form : and Aristotle has even been charged with inconsistency for 
 not doing so ; it has been said, that " in his Treatises of Ethics, Poli- 
 tics, &LC., he argues like a rational creature, and never attempts to 
 bring his own system into practice:" as well might a Chemist be 
 charged with inconsistency for making use of any of the compound 
 substances that arc commonly employed, without previously analyzing 
 and resolving them into their simple elements ; as well might it be 
 imagined that, to speak grammatically, means, to parse every sentence 
 
INTRODUCTION. 13 
 
 ■we utter. The Chemist (to pursue the illustration) keeps by him his 
 tests and his method of analysis, to be employed when any substance 
 is offered to his notice, the composition of which has not been ascer- 
 tained, or in which adulteration is suspected. Now a fallacy mav 
 aptly be compared to some adulterated compound ; it consists of an 
 ingenious mixture of truth and falsehood, so entangled, so intimately 
 blended, that the falsehood is (in the chemical phrase) held in solu- 
 tion: one drop of sound Logic is that test which immediately disunites 
 them, makes the foreign substance visible, and precipitates it to the 
 bottom. 
 
 But to resume the investigation of the principles of Reasoning : the 
 maxim resulting from the examination of a syllogism in the fore^oino- 
 form, and of the application of which every valid argument is in 
 reality an instance, is, " that whatever is predicated [i.e. affirmed or 
 denied) universally, of any class of things, may be predicated in like 
 manner, {viz. affirmed or denied,) of any thing comprehended in that 
 class." This is the principle, commonly called the dictum deomni et 
 nullo, for the establishment of Avhich we are indebted to Aristotle, and 
 which is the keystone of his whole Logical system. It is not a little 
 remarkable that some, otherwise judicious writers, should have been so 
 carried away by their zeal against that philosopher, as to speak with 
 scorn and ridicule of this principle, on account of its obviousness and 
 simplicity ; though they would probably perceive at once, in any other 
 case, that it is the greatest triumph of philosophy to refer many, and 
 seemingly very various, phenomena to one, or a very few, simple prin- 
 ciples ; and that the more simple and evident such a principle is, pro- 
 vided it be truly applicable to all the cases in question, the greater is its 
 value and scientific beauty. If, indeed, any principle be regarded as 
 not thus applicable, that is an objection to it of a different kind. Such 
 an objection against Aristotle's dictum, no one has ever attempted 
 to establish by any kind of proof; but it has often been taken for 
 granted; it being (as has been stated) very commonly supposed, with- 
 out examination, that the syllogism is a distinct kind of argument, and 
 that the rules of it do not apply, nor were intended to apply, to all 
 Reasoning whatever. Under this misapprehension, Campbell {Philo- 
 sophy of lihctoric) lahouvs, with some ingenuity, and not witliout an 
 air of plausibility, to show that every syllogism must be futile and 
 worthless, because the premises virtually assert the conclusion : little 
 dreaming, of course, that his objections, however specious, lie against 
 the process of Reasoning itself universally; and will therefore, of 
 course, apply to those very arguments which he is himself adducing. 
 
 It is much more extraordinary to find another author (l)ugald 
 Stewart) adopting, expressly, the very same objections, and yet 
 distinctly admitting within a few pages, the possibility of reducing 
 every course of argument to a series of syllogisms. 
 
 The same writer brings an objection against the dictum of Aristotle, 
 
14 IXTRODUCTION. 
 
 which it may be worth while to notice briefly, for the sake of setting 
 in a clearer light the real character and object of that principle. Its 
 application being, as has been seen, to a regular and conclusive syllo- 
 gism, he supposes it intended to prove and make evident the conclu- 
 siveness of such a syllogism ; and remarks how unphilosophical it is to 
 attempt giving a demonstration of a demonstration. And certainly 
 the charge would be just, if we could imagine the Logician's object to 
 be, to increase the certainty of a conclusion which we are supposed to 
 have already arrived at by the clearest possible mode of proof. But 
 it is very strange that such an idea should ever have occurred to one 
 who had even the slightest tincture of Natural Philosophy : for it 
 mio-ht as well be imagined that a Natural Philosopher or a Chemist's 
 design to strengthen the testimony of our senses by a priori reasoning, 
 and to convince us that a stone when thrown will fall to the ground, 
 and that gunpowder will explode when fired, because they show that 
 according to their principles those phenomena must take place as they 
 do. But it would be reckoned a mark of the grossest ignorance and 
 stupidity, not to be aware that their object is not to prove the existence 
 of an individual phenomenon, which our eyes have witnessed, but (as 
 the phrase is) to account for it : i.e. to show according to what priyi- 
 ciple it takes place ; — to refer, in short, the individual case to a 
 general law of nature. The object of Aristotle's dictum is precisely 
 analogous : he had, doubtless, no thought of adding to the force of 
 any individual syllogism ; his design was to point out the general 
 princi2:)le on which that process is conducted which takes place in each 
 syllogism. And as the laws of nature (as they are called) are in 
 reality merely generalized facts, of which all the phenomena coming 
 under them are particular instances ; so the proof drawn from Aris- 
 totle's dictum is not a distinct demonstration brought to confirm 
 another demonstration, but is merely a generalized and abstract state- 
 ment of all demonsti'ation whatever ; and is therefore in fact, the very 
 demonstration which [mutatis mutandis) accommodated to the various 
 subject matters, is actually employed in each particular case. 
 
 In order to trace more distinctly the different steps of the abstracting 
 process, by which any particular argument may be brought into the 
 most general form, we may first take a syllogism stated accurately 
 and at full length, such as the example formerly given, "whatever 
 exhibits marks of design, <fcc.," and then somewhat generalize the 
 expression, by substituting (as in Algebra) arbitrary unmeaning 
 symbols for the significant terms that were originally used ; the syllo- 
 gism will then stand thus: "every B is A ; C is B ; therefore C is 
 A." The Reasoning is no less evidently valid when thus stated, 
 whatever terms A, B, and C, respectively may be supposed to stand 
 for : such terms may indeed be inserted as to make aU, or any of, the 
 assertion syaZse; but it will still be no less impossible for any one who 
 admits the truth of the pre;mses, in an argument thus constructed, to 
 
INTRODUCTION. 15 
 
 deny the conclusion ; and this it is that constitutes the conclusiveness 
 of" an aro'unient. 
 
 Viewing then the syllogism thus expressed, it appears clearly, that 
 " A stands for any thing ivhatever that is predicated of a whole class," 
 [viz. of every B) " which comprehends or contains in it something else,'' 
 viz. C, of which B is, in the second premiss affirmed; and that 
 consequently the first term (A) is. in the conclusion, predicated of the 
 third C. 
 
 Now to assert the validity of this process, now before us, is to state 
 the very dictum we are treating of Avith hardly even a verbal alter- 
 ation, viz.: 
 
 1. Any thing whatever, predicated of a whole class, 
 
 2. Under which class something else is contained, 
 
 3. May be predicated of that w4iich is so contained. 
 
 The three members into which the maxim is here distributed, 
 correspond to the three propositions of the syllogism to which they 
 are intended respectively to fvpply. 
 
 The advantage of substituting for the terms, in a regular syllo- 
 gism, arbitrary unmeaning symbols such as letters of the alphabet, is 
 much the same as in Mathematics: the Reasoning itself is then 
 considered, by itself, clearly, and without any risk of our being misled 
 by the truth or falsity of the conclusion, which are, in fact, accidental 
 and variable ; the essential point being, as far as the argument is 
 concerned, the connection between the premises and the conclusions. 
 We are thus enabled to embrace the general principle of all Reasoning, 
 and to perceive its applicability to an indefinite number of individual 
 cases. That Aristotle, therefore, should have been accused of making 
 use of these s}Tnbols for the purpose of darkening his demonstrations, 
 and that too, by persons not unacquainted with Geometry and Algebra, 
 is truly astonishing. If a Geometer, instead of designating the four 
 angles of a square, by four letters, were to call them north, south, 
 east, and west, he would not render the demonstration of a theorem 
 the easier ; and the learner would be much more likely to be perplexed 
 in the application of it. 
 
 It belongs then exclusively to a syllogism, properly so called, [i.e. a 
 valid argument, so stated that its conclusiveness is evident from the 
 mere form of the expression,) that if letters or any other unmeanmg 
 symbols be substituted for the several terms, the validity of the 
 argument shall still be evident. Whenever this is not the case, the 
 supposed argument is either unsound and sophistical, or else may be 
 reduced, (without any alteration of its meaning) into the syllogistic 
 form; in which form, the test just mentioned may be applied to it. 
 
 What is called an unsound or fallacious argument, i.e. an apparent 
 argument which is, in reality, none, cannot, of course, be reduced into 
 this form ; but when stated in the form most nearly approaching to 
 this that is possible, its fallaciousness becomes more evident, from its 
 
16 INTRODUCTION. 
 
 nonconformity to the foregoing rule: e.g. "whoever is capable of 
 deliberate crime is responsible ; an infant is not capable of deliberate 
 crime; therefore, an infant is not responsible:" here, the term 
 " responsible " is affirmed universally of " those capable of deliberate 
 crime ;" it might, therefore, according to Aristotle's dictum, have been 
 affirmed of any thing contained under that class ; but in the instance 
 before us nothing is mentioned as contained under that class, only the 
 term infant is excluded from that class ; and though what is affirmed 
 of a whole class may be affirmed of any thing that is contained imder 
 it, there is no ground for supposing that it may be denied of whatever 
 is not so contained ; for it is evidently possible that it may be appli- 
 cable to a whole class and to something else besides : to say, e.g. that 
 all trees are vegetables, does not imply that nothing else is a vegetable. 
 It is evident, therefore, that such an apparent argument as the 
 above does not comj)ly with the ride laid down, and is consequently 
 invalid. 
 
 Again, in this instance, " food is necessary to life; corn is food ; 
 therefore corn is necessary to life:" the term "necessary to life " is 
 affirmed of food, but not universally; for it is not said of every kind 
 of food: the meaning of the assertion being manifestly that some food 
 is necessary to life : here again therefore the ride has not been com- 
 plied with, since that which is predicated, {i.e. affirmed or denied,) not 
 of the ivhole, but of a pait only of a certain class, cannot be predicated 
 of any thing, whatever is contained under that class. 
 
 The fallacy in this last case is, what is usually described in Logical 
 language as consisting in the "non-distribution of the middle term." 
 In order to understand this jDhrase, it is necessary to observe, that a 
 proposition being an expression in which one thing is affirmed or 
 denied of another; e.g. " A is B," both that of which something is 
 said, and that which is said of it, {i.e. both A and B,) are called 
 " Terms," from their being (in their nature) the extremes or bounda- 
 ries of the proposition ; and there are, of course, two, and but two, 
 terms in a proposition, (though it may so happen that either of them 
 may consist either of one word, or of several;) and a term is said to 
 be "distributed," when it is taken universally, so as to stand for 
 every thing it is capable of being applied to; and consequently 
 " undistributed," when it stands for a part only of the things signified 
 by it; thus, ''all food," or every kind of food, are expressions which 
 imply the distribution of the term "food;" ''some food" would imply 
 its non-distribution : and it is also to be observed, that the term of 
 which, in one premiss, something is affirmed or denied, and to which 
 in the other premiss something else is referred as contained in it, is 
 called the "middle " term in the syllogism, as standing between the 
 other two, {viz. the two terms of the conclusion,) and being the 
 medium of proof. Now it is plain, that if in each premiss a part only 
 of this middle term is employed, i.e. if it be not at all distributed, no 
 
INTRODUCTIOX. 17 
 
 conclusion can be drawn. Hence, if in the example formerly adduced, 
 it had been merely stated that *' something'" (not '^ivliatever,''' or 
 '•''every thing'") "which exhibits marks of design, is the work of an 
 intelligent author," it would not have followed, from the world's 
 exhibiting marks of design, that that is the work of an intelligent 
 author. 
 
 It is to be observed, also, that the words ** all," and "every," 
 which mark the distribution of a term, and " some," which marks its 
 non-distribution, are not always introduced: they are frequently 
 understood, and left to be supplied by the context; e.g. "food is 
 necessary;" viz. "some food;" "man is mortal;" viz. '' every man.'" 
 Propositions thus expressed are called by Logicians ^' indejinite," 
 because it is left undetermined by the form of the expression whether 
 the "subject," (the term of which something is affirmed or denied 
 being called the " subject " of the proposition, and that which is said 
 of it, the " predicate ") be distributed or not. Nevertheless it is plain 
 that in every proposition the subject either is, or is not, distributed, 
 though it be not declared whether it is or not ; consequently every 
 proposition, whether expressed indefinitely or not, must be either 
 "universal " or "particular;" those being called universal, in which 
 the predicate is said of the whole of the subject, (or in other words, 
 where the subject is distributed ;) and those, particular, in which it is 
 said only of a part of the subject: e.g. "AH men are sinful," is 
 universal; "some men are sinful," particular: and this division of 
 propositions is in Logical language said to be according to their 
 ^^ quantity.'''' 
 
 But the distribution or non-distribution of the predicate is entirely 
 independent of the quality of the proposition; nor are the signs "all" 
 and "some" ever affixed to the predicate; because its distribution 
 depends upon, and is indicated by the ''quality " of the proposition ; 
 i.e. its being affirmative or negative ; it being a universal rule, that 
 the predicate of a negative proposition is distributed, and, of an 
 affirmative, undistributed. The reason of this may easily be under- 
 stood, by considering that a term which stands for a whole class may 
 be applied to [i.e. affirmed of) any thing that is comprehended under 
 that class, though the term of which it is thus affirmed may be of 
 much narrower extent than that other, and may, therefore, be far 
 from coinciding with the loholc of it : thus it may be said with truth, 
 that " the Negroes arc uncivilized," though the term uncivilized be of 
 much wider extent than "Negroes," comprehending, besides them, 
 Hottentots, kc: so that it would not be allowable to assert, that ''all 
 who are uncivilized are Negroes;" it is evident, therefore, that it is 
 a part only of the term "uncivilized" that has been affirmed of 
 "Negroes:" and the same reasoning applies to every affirmative 
 proposition ; for though it may so happen that the subject and predi- 
 cate coincide, i.e. are of equal extent, as, e.g. "all men are rational 
 
 c 
 
18 INTRODUCTION. 
 
 animals," (it being equally true, that " all rational animals are men,") 
 yet this is not imjMed by the form of the expression; since it would be 
 no less true, that " all men are rational animals," even if there were 
 other rational animals besides man. 
 
 It is plain, therefore, that \i any p)Cift of the predicate is applicable 
 to the subject, it may be affirmed, and, of course, cannot be denied of 
 that subject ; and consequently, when the predicate is denied of the 
 subject, it is implied that no part of that predicate is applicable to 
 that subject ; i.e. that the ivhole of the predicate is denied of the 
 subject: for to say, e.g. that "no beasts of prey ruminate," implies 
 that beasts of prey are excluded from the whole doss of ruminant 
 animals, and consequently that "no ruminant animals are beasts of 
 prey." And hence results the above mentioned rule, that the distri- 
 bution of the predicate is implied in negative propositions, and its 
 nondistribution in affirmatives. 
 
 It is to be remembered, therefore, that it is not sufficient for the 
 middle term to occur in a universal proposition, since if that proposi- 
 tion be an affirmative, and the middle term be the p)redicate of it, it 
 will not be distributed ; e.g. if in the example formerly given it had 
 been merely asserted, that "all the works of an intelligent author 
 show marks of design," and that "the universe shows marks of 
 design," nothing could have been proved; since, though both these 
 propositions are universal, the middle term is made the predicate in 
 each, and both are affirmative ; and accordingly the rule of Aristotle 
 is not here complied with, since the term, " work of an intelligent 
 author," which is to be proved applicable to "the universe," is not 
 affirmed of the middle term, ("what shows marks of design,") under 
 which " universe " is contained ; but the middle term on the contrary 
 is affiraied of it. 
 
 If, however, one of the premises be negative, the middle term may 
 then be made the predicate of it, and will thus, according to the above 
 remark, be distributed: e.g. " no ruminant animals are predacious; 
 the lion is predacious; therefore the lion is not ruminant:" this is a 
 valid syllogism ; and the middle term (predacious) is distributed by 
 being made the predicate of a negative proposition. The form, indeed, 
 of the syllogism, is not that prescribed by the dictum of Aristotle, 
 but it may easily be reduced to that form, by stating the first 
 proposition thus ; no predacious animals are ruminant ; which is 
 manifestly implied (as was above remarked) in the assertion, that "no 
 ruminant animals are predacious." The syllogism will thus appear 
 in the fonn to which the dictum applies. 
 
 It is not every argument, indeed, that can be reduced to this 
 form by so short and simple an alteration as in the case before us : a 
 longer and more complex process will often be required ; and rules 
 will hereafter be laid down to facilitate this process in certain cases : 
 but there is no sound argument but v.hat can be reduced into this form, 
 
INTRODUCTION. 19 
 
 without at all departing from the real meaning and drift of it : and the 
 form will be found (though more prolix than is needed for ordinary 
 use) the most perspicuous in which an argument can be exhibited. 
 
 All reasoning whatever, then, rests on the one simple principle laid 
 down by Aristotle; that, " what is predicated, either affirmatively or 
 negatively, of a term distributed, may be predicated, in like manner, 
 (i.e. affirmatively or negatively,) of any thing contained under that 
 term." So that when our object is to prove any proposition, i.e. to 
 show that one term may rightly be affirmed or denied of another, the 
 process which really takes place in our minds is, that we refer that 
 term (of which the other is to be thus predicated,) to some class, {i.e. 
 middle term,) of which that other may be affirmed, or denied, as the 
 case may be. Whatever the subject matter of an argument may be> 
 the Reasoning itself, considered by itself, is in every case the same 
 process ; and if the writers against Logic had kept this in mind, they 
 would have been cautious of expressing their contempt of what they 
 call *' syllogistic Reasoning," which is in truth all Reasoning ; and 
 instead of ridiculing Aristotle's principle for its obviousness and 
 simplicity, would have perceived that these are in fact its highest 
 praise : the easiest, shortest, and most evident theory, provided it 
 answer the purpose of explanation, being ever the best. 
 
 If we conceive an inquirer to have reached, in his investigation of 
 the theory of Reasoning, the point to which we have now arrived, a 
 question w^hich would be likely next to engage his attention, is, that 
 of predication ; i.e. since in Reasoning we are to find a middle term, 
 which may be predicated affirmatively of the subject in question, we 
 are led to inquire what terms may be affirmed, and what denied, of 
 what others. 
 
 It is evident that proper names, or any other terms, which denote 
 each but a single individual, as *' Csesar," "the Thames," *' the 
 Conqueror of Pompey," '* tills river," (hence called in Logic, 
 " singular terms,") cannot be affirmed of any thing besides themselves, 
 and are therefore to be denied of any thing else ; we may say, *' this 
 river is the Thames," or ** Caesar was the conqueror of Pompey ;" 
 but w^e cannot say of any thing else that is the Thames. 
 
 On the other hand, those terms which are called ** common," as 
 denoting any one individual of a whole class, as " river," " conqueror," 
 may of course be affirmed of any, or all that belong to that class ; as, 
 " the Thames Is a river ;" " the Rhine and the Danube arc rivers." 
 
 Common terms, therefore, are called " prcdicables," {viz. affirma- 
 tively predicable,) from tlieir capability of being affirmed of others : 
 a singular term, on the contrary, may be subject of a proposition, but 
 never the predicate, unless it be of a negative proposition ; (as, e.c/. 
 the fii-st-born of Isaac was not Jacob;) or, unless tlie subject and 
 predicate be only two expressions for the same individual object, as in 
 some of the above instances. 
 
20 INTRODUCTION. 
 
 The process bj which the mind arrives at the notions expressed by 
 these " common" (or in popular language, " general") terms, is 
 properly called generalization ; though it is usually (and truly) said to 
 be the business of abstraction ; for generalization is one of the pur- 
 poses to which abstraction is applied : when we draiu off, and con- 
 temiolate sejxirately, any part of an object presented to the mind, dis- 
 regarding the rest of it, we are said to abstract that part. Thus, a 
 person might, when a rose was before his eyes or mind, make the 
 scent a distinct object of attention, laying aside all thought of the 
 colour, form, &c.; and thus, though it were the only rose he had 
 ever met with, he would be employing the faculty of abstraction ; but 
 if, in contemplating several objects, and finding that they agree in 
 certain points, we abstract the circumstances of agreement, disre- 
 garding the differences, and give to all and each of these objects 
 a name apphcable to them in respect of this agreement, i.e. a common 
 name, (as "rose,") we are then said to generalize. Abstraction, 
 therefore, does not necessarily imply generalization, though gener- 
 alization implies abstraction. 
 
 Much needless difficulty has been raised respecting the results of 
 this process ; many having contended, and perhaps more having taken 
 for granted, that there must be some really existing thing, corre- 
 sponding to each of these general or common terms, and of which 
 such term is the name, standing for and representing it : e.g. that as 
 there is a really existing being corresponding to the proper name 
 ^tna, and signifying it, so the common term '* mountain," must 
 have some one really existing thing corresponding to it, and of course 
 distinct from each individual mountain, (since the term is not singular, 
 but common,) yet existing m each, since the term is applicable to 
 each of them. " When many different men," it is said, " are at the 
 same time thinking or speaking about a mountain, i.e. not any par- 
 ticular one, but a mountain generally, their minds must be all 
 employed on sometliing ; which must also be one thing, and not 
 several, and yet cannot be anyone individual:" and hence avast 
 train of mystical disquisitions about ideas, &c. has arisen, which are 
 at best nugatory, and tend to obscure our view of the process which 
 actually takes place in the mind. 
 
 The fact is, the notion expressed by a common term is merely an 
 inadequate (or incomplete) notion of an individual ; and from the very 
 circumstance of its inadequacy, it will apply equally well to any one 
 of several individuals : e.g. if I omit the mention and the considera- 
 tion of every circumstance which distinguishes -^tna from any other 
 mountain, I then form a notion (expressed by the common term 
 mountain) which inadequately designates iEtna, and is equally appli- 
 cable to any one of several other individuals. 
 
 Generalization, it is plain, may be indefinitely extended by a 
 further abstraction applied to common terms : e.g. as by abstraction 
 
INTRODUCTION 21 
 
 from the term Socrates, we obtain the common term philosopher ; 
 so from "philosopher," by a similar process, we arrive at the more 
 general term " man ;" from " man" to " animal," (fee. 
 
 The employment of this faculty at pleasure lias been regarded, and 
 perhaps with good reason, as the characteristic distinction of the 
 human mind from that of the brutes. We are thus enabled, not only 
 to separate, and consider singly, one part of an object presented to 
 the mind, but also to fix arbitrarily upon whatever part we please, 
 according as may suit the purpose we happen to have in view : e.g. 
 any individual person to whom we may direct our attention, may be 
 considered either in a political point of view, and accordingly referred 
 to the class of merchant, farmer, lawyer, &c. as the case may be ; or 
 physiologically, as negro, or white man ; or theologically, as Pagan or 
 Christian, Papist or Protestant ; or geographically, as European, 
 American, &lq. (fee. And so, in respect of any thing else that may be 
 the subject of our Reasoning : we arbitrarily iix upon and abstract 
 that point which is essential to the purpose in hand ; so that the 
 same object may be referred to various diiferent classes, according to 
 the occasion. Not, of course, that we are allowed to refer any thing 
 to a class to which it does not really belong ; which would be pre- 
 tending to abstract from it something that was no part of it ; but 
 that we arbitrarily fix on any ^;ar^ of it which we choose to abstract 
 from the rest. It is important to notice this, because men are often 
 disposed to consider each object as really and properly belonging to 
 some one class alone, from their having been accustomed, in the 
 course of their own pursuits, to consider in one point of view only 
 things which may with equal propriety be considered in other points 
 of view also : i.e. referred to various classes, (or predicates.) And 
 this is that which chiefly constitutes what is called narrowness of 
 mind : e.g. a mere Botanist might be astonished at hearing such 
 plants as clover and lucerne included, in the language of a farmer, 
 under the term " grasses," which he has been accustomed to limit 
 to a tribe of plants widely different in all Botanical characteristics ; 
 and the mere farmer might be no less surprised to find the trouble- 
 some " weed," (as he has been accustomed to call it,) known by the 
 name of couch grass, and which he has been used to class with 
 nettles and thistles, to which it has no Botanical aftinity, ranked by 
 the Botanist as a species of wheat, {Tr'dlciim Rcpcns.) And yet 
 neither of these classifications is in itself erroneous or irrational ; 
 though it Avould be absurd in a Botanical treatise to class plants 
 according to their Agricultural use ; or in an Agricultural treatise, 
 according to the structure of their flowers. 
 
 The utility of these considerations, with a view to the present 
 subject, will be readily estimated, by recurring to the account which 
 has been already given of the process of Reasoning; the analysis of 
 which shows, that it consists in referring the term we are S2)caking of 
 
22 INTRODUCTION. 
 
 to some class, i^iz. a middle term ; wliich term again is referred to or 
 excluded from (as the case may be) another class, viz. the term which 
 we wish to affirm or deny of the subject of the conclusion. So that 
 the quality of our Reasoning in any case must depend on our being 
 able, correctly, clearly, and promptly, to abstract from the subject in 
 question that which may furnish a middle term suitable to the 
 occasion. 
 
 The imperfect and irregular sketch which has here been attempted, 
 of the Logical System, may suffice (even though some parts of it 
 should not be at once fully understood by those who are entirely 
 strangers to the study) to point out the general drift and purpose of 
 the Science, and to render the details of it both more interesting and 
 more intelligible. The analytical form, wdiich has here been adopted, 
 is, generally speaking, the best suited for introdudng any science in 
 the plainest and most interesting form ; though the synthetical, which 
 will henceforth be employed, is the most regular and the most com- 
 pendious form for storing it up in the memory 
 
CHAPTER I. 
 
 OF THE OPERATIONS OF THE MIND AND OF TERMS. 
 
 There are three operations of the mind which are concerned in 
 argument : 1st. Simple Apprehension ; 2d. Judgment ; 3d. Discourse 
 or Reasoning. 1st. Simple apprehension is the notion (or conception) 
 of any object in the mind, analogous to the perception of the senses. 
 It is either incomplex or complex: incomplex apprehension is of one 
 object, or of several without any relation being perceived between 
 them, as of " a man," " a horse," " cards :" complex is of several 
 Vj'dh such a relation, as of " a man on horseback," " a pack of cards." 
 
 2d. Judgment is the comparing together in the mind two of the 
 notions, (or ideas,) whether complex or incomplex, which are the 
 objects of apprehension, and pronouncing that they agree or disagree 
 with each other ; (or that one of them belongs or does not belong to 
 the other.) Judgment therefore is either affirmative or negative. 
 
 3d. Reasoning (or discourse) is the act of proceeding from one 
 judgment, to i\.noi\\QY founded upon it, (or the result of it.) 
 
 § 2. Language affords the signs by which these operations of the 
 mind are expressed and communicated. An act of Apprehension 
 expressed in language, is called a Term; an act of Judgment, a Pro- 
 position ; an act of Reasoning j an Argument or Syllogism ; as e.g. 
 
 " Every dispensation of Providence is beneficial; 
 iVfflictions are dispensations of Providence, 
 Therefore they arc beneficial :" is a Syllogism ; 
 
 (the act of Reasoning being indicated by the word '^therefore,''') it 
 consists of three Propositions, each of which has (necessarily) two 
 Terms, as " beneficial," " dispensations of Providence," tkc. 
 
 Language is employed for various purposes, e.g. the province of an 
 liistorian is to convey information; of an orator, to persuade, etc. 
 Logic is concerned with it only when employed for the purpose of 
 Reasoning, {i.e. in order to convince;) and whereas, in reasoning. 
 Terms are liable to be indistinct, {i.e. without any clear determinate 
 meaning,) Propositions, to be false, and Arguments, iiicon elusive. 
 Logic undertakes directly and com]>letcly to guard against f/ds last 
 defect, and incidentally and in a certain degree against the others, as 
 far as can be done by the p)^'op^^' ^^^^ ^f l<^^^{juage: it is, therefore. 
 
24 OF THE OPERATIONS OF THE MIND AND OF TERMS. [Chap. I. 
 
 (when regarded as an art^) *' the art of employing language properly 
 for the purpose of Reasoning." Its hnportance no one can rightly 
 estimate who has not long and attentively considered how much our 
 thoughts are influenced hy words, and how much error, perplexity, 
 and lahour, are occasioned by a faulty use of language. 
 
 A Syllogism being, as aforesaid, resolvable into three Propositions, 
 and each Proposition containing two Terms ; of these Terms, that 
 which is spoken of, is called the Subject; that which is said of it, the 
 Predicate; and these two together are called the Terms, (or extremes,) 
 because, logically, the subject is placed^rs^, and the predicate last: 
 and, in the middle, the Copula, which indicates the act of Judgment, 
 as by it, the Predicate is affirmed or denied of the Subject. It must 
 be either is or is not ; the substantive verb being the only verb recog- 
 nised by Logic: all others are resolvable, by means of the verb, " to 
 be," and a participle or adjective; e.g. " the Romans conquered : " 
 the word " conquered" is both Copula and Predicate, being equivalent 
 to " loere (Cop.) victorious " (Pred.)^ 
 
 § 3. It is evident that a Term may consist either of one Avord or 
 of several ; and that it is not every word that is capable of being 
 employed by itself as a Term; e.g. adverbs, prepositions, (fc;c.,'and 
 also nouns in any other case besides the nominative. A noun may be 
 by itself a Term ; a verb (all except the substantive verb used as the 
 Copula,) is resolvable into the Copula and Predicate, to Avhich it is 
 equivalent, and indeed is often so resolved in the mere rendering out 
 of one language into another; as " ipse adest/' he is present. It is 
 to be observed, however, that under " verb," Ave do not include the 
 infinitive, which is properly a noun substantive, nor the participle, 
 Avhich is a noun adjective. They are verbals, being related to their 
 respective verbs in respect of the things they signify; but not verbs, 
 inasmuch as they differ entirely in their mode of signification. It is 
 vrorth observing, that an infinitive (though it often comes last in the 
 sentence) is never the Predicate, except when another infinitive is the 
 Subject. It is to be observed, also, that in English there are two 
 infinitives, one, in '' ing," the same in sound and spelling as the 
 participle present, from Avhich, however, it should be carefully distin- 
 
 1 It is to be observed, however, that as agreement of two given terms : hence, if 
 a science is conversant about knowledge any other tense of tlie substantive verb, be- 
 only, an art is the apjMcation of know- sides the present, is used, it is either to be 
 ledge to prfflcZ/ce,- hence Logic (as well as understood as the same in sense, (the 
 any other system of knowledge) becomes, ditference of tense being regarded as a 
 when applied to practice, an art; while matter of grammatical convenience only ;) 
 confined to the theory of Reasoning, it is or else, it the circumstance of time really 
 strictly a science : and it is as such that it do inodi/y the sense of the whole proposi- 
 occupies the higher place in point of dig-_ tion, so as to make the use of that tense an 
 nity, since it professes to develop some of essential, then this circumstance is to be 
 the most interesting and curious intellec- regarded as a part of one of the terms : 
 tual phenomena. '"'' at thai time," or some such expression, 
 
 being understood. Sometimes the sub- 
 
 2 It is proper to observe, that the Copula, stantive verb is both Copula and Predi- 
 as such, has no relation to time; but cate; i.e. where existence only is predi- 
 expresses merely the agreement or dis- cated: e.^;. Deus es^. 
 
Chap. I.] OF THE OPERATIONS OP THE MIND AND OF TERMS. 25 
 
 giiished; e.g. " rising early is healthful," and " it is healthful to rise 
 early," are equivalent. 
 
 An adjective (including participles) cannot, by itself, be made the 
 Subject of a Proposition ; but is often employed as a Predicate ; as 
 " Crassus was rich; " though some choose to consider some substan- 
 tives as understood in every such case, {e.g. rich mau) and consequently 
 do not reckon adjectives among simple Terms ; i.e. words which are 
 capable, simply, of being employed as Terms. This, however, is a 
 question of no practical consequence. 
 
 Of simple Terms, then, (which are what the first part of Logic 
 treats of) there are many divisions;^ of which, however, one will be 
 sufficient for the present purpose; viz. into singular and common; 
 because, though any Term whatever may be a Subject, none but a 
 common Term can be affirmatively predicated of severed others. A 
 singular Term stands for one individucd, as "Ca3sar." *' the Thames;" 
 (these, it is plain, cannot be said [or predicated] affirmativcli/, of any 
 thing but themselves.) A common Term stands for several individuals: 
 i.e. can be applied to any of them, as comprehending them in its 
 single S'ignijication ; as "man," "river," "great." The notions 
 expressed by these common Terms, we are enabled to form, by the 
 faculty of abstraction: for by it, in contemplating any object (or 
 objects,) we can attend exclusively to some particular circmustances 
 belonging to it, [some certain parts of its nature as it were] and quite 
 withhold our attention from the rest. When, therefore, we are thus 
 contemplating several individuals which i^esemhle each other in some 
 part of their nature, we can (by attending to that part cdone, and not 
 to those points in which they differ) assign them one common name, 
 wdiich will express or stand for them merely as far as they all agree; 
 aud which of course will be applicable to all or any of them ; (which 
 process is called generalization,) and each of these names is called a 
 common Term, from its belonging to them all alike; or a PredicaUey 
 because it may be predicated affirmatively of them, or of any one of 
 them. 
 
 Generalization (as has been remarked) implies abstraction, but it is 
 not the same thing ; for there may be abstraction without generaliza- 
 tion : when we are speaking of an individual, it is usually an abstract 
 notion that avc form ; e.g. suppose we are speaking of the present 
 ex-King of France ; he must actually be either at Paris or elsewhere ; 
 sitting, standing, or in some other posture ; and in such and such a 
 dress, tfec. Yet many of these circumstances, (which are separable 
 accidents, (vide § 7.) and consequently) which are regarded as non- 
 essential to the individual, arc quite disregarded by us ; and we cd>stract 
 
 3 The usual divisions of words into uni- ofcmjiloyiu'i tliem: tlio s^imc word may bo 
 
 vocal, equivocal, and analof,^ou3, and into employed either univocally, e(iuivocally, 
 
 words of the first and second intention, or analof^onsly ; either in the tii-st inlen- 
 
 however, are not, strictly si)eakiiifr, divi- tion or in the second, 
 sions of words, but divisions of the manner 
 
26 OF THE OPERATIONS OF THE MIND AND OF TERMS. [Chap. I. 
 
 from tliem -what avc consider as essential; thus forming an abstract 
 notion of the individual. Yet there is here no generalization. 
 
 § 4. Whatever Term can be affirmed of several things, must express 
 either their lohole essence, which is called the Sjyecies; or a j^cirt 
 of their essence, {viz. either the material part, which is called the 
 Genus, or the formal and distinguishing 2^cirt, which is called Differ- 
 entia,) or in common discourse, characteristic, or something joined to 
 tJie essence, whether necessarily, which is called a iwoperty, or contin- 
 gently, which is an accident. 
 
 Every Predicable expresses either 
 
 The ichole essence or part of its or something 
 
 of its subject : essence joined to its 
 
 viz. Species — | essence 
 
 r- — "^ ^ 
 
 Genus — Difference. 
 
 Property Accident 
 
 universal peculiar universal 
 
 but not but not and pe- 
 
 peculiar luiiversal cidiar. inseparable — separable. 
 
 It is evident from what has been said, that the Genus and Differ- 
 ence put together make up the Species: e.g. "rational" and 
 "animal" constitute "man;" so that, in reality, the Species con- 
 tains the Genus {i.e. implies it ;) and when the Genus Is called a whole, 
 and is said to contain the Species, this is only a metaphorical expres- 
 sion, signifying that it comprehends the Species, in its own more 
 extensive signification: e.g. if I predicate of Caesar that he is an 
 animal, I say the truth indeed, but not the ivhole truth ; for he is not 
 only an animal, but a man ; so that " man " is a vaore full and com- 
 plete expression than "animal;" which for the same reason is more 
 extensive, as it contains, (or rather comprehends) and may be predi- 
 cated of, several other Species, i.e. "beast," "bird," &c. In the 
 same manner the name of a Species is a more extensive, but less full 
 and complete term than that of an individual, {viz. a singular term ;) 
 since the Species may be predicated of each of these. [Note, that 
 Genus and Species are commonly said to ho. predicated in quid, {r\) {i.e. 
 to answer to the question "what?" as, " what is Co3sar?" Answer, 
 " a man: " " what is a man? " Answer, " an animal.") Difference, 
 in " quale quid;^^ {ttoicv n) Property and Accident in quale {Trohv).^ 
 
 § 5. A Genus, which is also a Species, is called a sfuhaltern Genus 
 or Species ; as " bird," which is the Genus of " pigeon," {i.e. of which 
 " pigeon " is a Species) is itself a Species of " animal." A Genus 
 
Chap. I.] OP THE OPERATIONS OF THE MIND AND OP TERMS. 
 
 -/ 
 
 which is '}iot considered as a Species of any thing, is called summum 
 (the highest) Genus ; a Species which is not considered as a Genus of 
 any thing, i.e. is regarded as containing under it only individuals^ is 
 called injima (the loAvest) Species. 
 
 When I say of a magnet, that it is "a kind of iron ore,'^ that is 
 called its j^roximum Genus, because it is the closest (or lowest) Genus 
 that can be predicated of it: " mineral" is its more remote Genus. 
 
 When I say that the Differentia of a magnet is its " attracting 
 iron,'' and that its Prope?'^?/ is *' j^olariti/,'' these are called respec- 
 tively a specific Difference and Property ; because magnet is an injima 
 Species, {i.e. only a Species.) 
 
 When I say that the Differentia of iron ore is its " containing iron,'' 
 and its Property '' being attracted by the magnet," these are called 
 respectively, a generic Difference and Property, because iron ore is a 
 subaltern Species or Genus, being both the Genus of magnet, and a 
 Species of mineral. 
 
 That is the most strictly called a Property, which belongs to the 
 wJwle of a Species, and to that Species alone; as polarity to the 
 magnet. [xVnd such a p)foperty, it is often hard to distinguish from 
 the Differentia; but whatever you consider as the most essential to the 
 nature of a Species with respect to the matter you are engaged in, 
 you must call the Differentia; as "rationality" to "man;" and 
 whatever you consider as rather an accompaniment (or result) of that 
 Difference, you must call the Property; as the " use of speech" 
 seems to be a result of rationality.] But very many Properties which 
 belong to the ivhole of a Species are not peculiar to it ; as, " to breathe 
 air" belongs to every man, but not to man alone ; and it is, therefore, 
 strictly speaking, not so much a Property of the Species " man," as 
 of the higher, i.e. more comprehensive, Species, which is the Genus 
 of that, viz. of " land animal." Other Properties, as some Logicians 
 call them, are j^^culiar to a Species, but do not belong to the whole of 
 it : e.g. man cdone can be a poet, but it is not every man that is so. 
 These, however, are more commonly and more properly reckoned as 
 Accidents. 
 
 For that is most properly called an Accident, which may be absent 
 or present, the essence of the Species continuing the same ; as, for a 
 man to be " ivalking," or a " native of Paris:" of these two examples, 
 the former is what Logicians call a separable Accident, because it 
 may l3c separated from the individual: {e.g. he may sit down;) the 
 latter is an inseparable Accident, being not separable from the indivi- 
 dual, {i.e. he who is an individual of Paris can never be otherwise ;) 
 " from the individual," I say, because every Accident must be separ- 
 able from the Species, else it would be a Projjcrty. 
 
 Let it here be observed, that both the general name ** Prcdicable," 
 and each of the classes of Predicables, {viz. Genus, Species, itc.) are 
 relative; i.e. wo cannot say ivluii Predicable any Term is, or whether 
 
28 OF THE OPERATIONS OF THE MIND AND OF TERMS. [Chaf. I. 
 
 it is any at all, unless it be specified of ivliat it is to be predicated : 
 e.g. tbe Term " red " would be considered a Genus, in relation to the 
 Terms " pink," *' scarlet," &c., it might be regarded as the Differ- 
 eMia, in relation to " red rose ;" — as a property of " blood;" — as an 
 Accident of " a house," &c. 
 
 And universally, it is to be steadily kept in mind, that no " com- 
 mon Terms" have, as the names of individuals have, any real thing 
 eodsting in nature corresponding to them ; {roli n, as Aristotle 
 expresses it, though he has been represented as the champion of the 
 opposite opinion: vide Categ. c. 3.) but is merely a name denoting a 
 certain i?iadequate notion which our minds have formed of an indivi- 
 dual, and which, consequently, not including any thing wherein that 
 individual differs from certain others, is applicable equally well to all 
 or any of them: thus " man " denotes no real thing (as the sect of 
 the Realists maintained,) distinct from each individual, but merely, 
 any man, viewed inadequately, i.e. so as to omit and abstract from all 
 that is peculiar to each individual ; by which means the Term becomes 
 applicable alike to any one of several individuals, or (in the plural) to 
 several together ; and we arbitrarily fix on the circumstance which we 
 thus choose to abstract and consider separately, disregarding all the 
 rest ; so that the same individual may thus be referred to any of 
 several difterent Species, and the same Species to several Genera, as 
 suits our purpose. Thus it suits the farmer's purpose to class his 
 cattle with his ploughs, carts, and other possessions, under the name 
 of ''stock:'" the naturalist, suitably to his purpose, classes them as 
 " quadrupeds,'' which Term would include wolves, deer, &c., which 
 to the farmer would be a most improper classification : the commissary, 
 again, would class them with corn, cheese, fish, &c., as '^provision.'''' 
 That which is most essential in one view, being subordinate in another. 
 
 § 6. An individual is so called because it is incapable of logical 
 Division; which is a metaphorical exjDression to signify *' the distinct 
 {i.e. separate) enumeration of several things signified by one common 
 name." This operation is directly opposite to generalization, (which 
 is performed by means of abstraction;) for as in that, you lay aside 
 the difference by which several things are distinguished, so as to call 
 them all by one common name, so, in division, you add on the difi'er- 
 ences, so as to enumerate them by their several particular names. 
 Thus, "mineral" is said to be divided into " stones, metals," (fee; 
 and metals again into "gold, iron," &c., and these are called the 
 parts (or members) of the Division. 
 
 The rules for Division are three: 1st, each of the parts, or any of 
 them short of all, must contain less {i.e. have a narrower signification) 
 than the thing divided. 2d. All the parts together must be exactly 
 equal to the thing divided ; (therefore we must be careful to ascertain 
 that the summum Genus may be predicated of every Term placed 
 under it, and of nothing else.) 3d. The parts or members must be 
 
Chap. I.] OF THE OPERATIOXS OF THE MIND AND OF TERMS. 29 
 
 opposed; i.e. must not be contained in one another: e.g. if you were 
 to divide "book" into "poetical, historical, folio, quarto, French, 
 Latin," &c., the members would be contained in each other; for a 
 French book may be a quarto, and a quarto, French, k.c. You must 
 be careful, therefore, to keep in mind the prbiciple of Division with 
 which you set out: e.g. Avhether you begin dividing books according 
 to their matter, their language, or their size, &c., these being also so 
 many cross Divisions. And when any thing is capable (as in the above 
 instance) of being divided in several diflferent ways, we are not to 
 reckon one of these as the true, or real, or right one, without specify- 
 ing what the object is M'hich we have in view: for one mode of 
 dividing may be the most suitable for one purpose, and another, for 
 another ; as, e.g. one of the above modes of dividing books would be 
 the most suitable to a bookbinder ; another in a philosophical, and the 
 other in a philological view. 
 
 It must be carefully remembered, that the word "Division," as 
 employed in Logic, is, as has been observed already, meta2:)horical ; 
 for to divide, means originally and properly to separate the component 
 parts of any thing, each of which is of course absolutely less than the 
 whole: e.g. a tree {i.e. any individual tree) might be divided "phy- 
 sically," as it is called, into root, trunk, branches, leaves, &c. Now 
 it cannot be said that a root or a leaf is a tree : whereas in a Logical 
 Division each of the members is, in reality, more than the whole: e.g. 
 if you divide tree {i.e. the Genus, tree) into oak, ash, elm, tfec, we may 
 say of the oak, or of any individual oak, that " it is a tree ;" for by 
 the very word " oak," we express not only the general notion of a 
 tree, but more, viz. the peculiar characteristic {i.e. difference) of that 
 kind of tree. 
 
 It is plain, then, that it is logically only, i.e. in our mode of speak- 
 ing, that a Genus is said to contain (or rather, comprehend) its Species ; 
 while metaphysically, i.e. in our conceptions, a Species contains, i.e. 
 implies, its Genus. 
 
 Care must be taken not to confound a physical Division witli a 
 Logical, against Avhich a caution is given under R. I. 
 
 § 7. Definition is another metaphorical word, which literally sig- 
 nifies, " laying do^^■n a boundary ;" and is used in Logic to signify an 
 expression which explains any term, so as to separate it from every 
 thing else, as a boundary separates fields. A nominal Definition 
 (such as are those usually found in a didionaiy of one's own lan- 
 guage) explains only the meaning of the term, by giving some equiva- 
 lent expression, wliich may happen to be better known. Thus you 
 might define a "Term," that which forms one of the extremes or 
 boundaries of ci " Proposition;" and a " Predicablc," that which may 
 be predicated; "decalogue," ten commandments; "telescope," an 
 instrument for viewing distant objects, c^'c. A real Definition is one 
 wliich explains and unfolds the nature of the thing; and each of these 
 
30 OF THE OPERATIONS OF THE MIND AND OF TERMS. [Chap. i. 
 
 kinds of Definition is either accidental or essential. An essential Defi- 
 nition assigns (or lays down) the C07istiiuent parts of the essence, (or 
 nature.) An accidental Definition (which is commonly called a Des- 
 crlj)tion) assigns the circmiistances belonging to the essence, viz. 
 Properties and Accidents, {e.g. causes, effects, <fec.) thus, "man" 
 may be described as *' an animal that uses fire to dress his food," etc. 
 [And here note, that in describing a Species, you cannot mention any 
 thing which is strictly an Accident, because if it does not belong to 
 the ivhole of the Species, it cannot define it : in describing an indi- 
 vidual, on the contrary, you enumerate the Accidents, because by 
 them it is that one individual differs from another, and in this case 
 you add the Species: e.g. " Philip was a man of Macedon, who sub- 
 dued Greece," &c. Individuals, it is evident, can be defined in this 
 way alone.] 
 
 Lastly, the essential Definition is divided into 2')hysiGal {i.e. natural) 
 and Logical or Metaphysical: the physical Definition lays down the 
 real parts of the essence which are actually separable ; the logical, lays 
 down the ideal parts of it, which cannot be separated except in the 
 mind: thus, a plant would be defined 2^hysically, by enumerating the 
 leaves, stalks, roots, &c., of which it is composed: logically, it would 
 be defined an organized being, destitute of sensation ; the former of 
 these expressions expressing the Genus, the latter, the Difference : 
 for a logical Definition must ahvays consist of the Genus and Differentia, 
 which are the parts of which Logic considers every thing as consist- 
 ing, and which evidently are separable in the onind alone. Thus 
 " man" is defined '* a rational animal," <t;c. So also a '* Proposition" 
 might be defined, physically, a Subject and Predicate combined by a 
 Copula : the parts here enumerated being actually separable ; but 
 logically it would be defined " a sentence which affirms or denies;" 
 and these two parts of the essence of a Proposition (which are the 
 Genus and Differentia of it) can be separated in the mind only. And 
 note, that the difference is not always one quality, but is frequently 
 compounded of several together, no one of which would alone suffice. 
 
 Definitions are divided into nominal and real, according to the 
 object accomplished by them ; w^hcther to explain, merely, the meaning 
 of the word, or the nature of the thing : they were divided into acci- 
 dental, physical, and logical, according to the means emp)loyed by each 
 for accomplishing their respective objects, whether it be the enumera- 
 tion of attributes, or of the physical or the metaphysical parts of the 
 essence. These, therefore, are evidently two cross divisions. Li this 
 place we are concerned with nominal Definitions only, (except, indeed, 
 of logical Terms,) because all that is requisite for the purposes of 
 Reasoning (which is the proper province of Logic,) is, that a Term 
 shall not be used in different senses: a real Definition of any thing 
 belongs to the science or system which is employed about that thing. 
 It is to be noted, that in Mathematics the nominal and real Defini- 
 
Chap. I.] OF THE OPERATIONS OF THE MIND AND OF TERMS. 31 
 
 tiou exactly coincide ; the meaning of the luord, and the nature of the 
 thing, being exactly the same. This holds good also with respect to 
 logical Terms, most legal, and many ethical terms. 
 
 It is scarcely credible how much confusion has arisen from the 
 ignorance of these distinctions which has prevailed among logical 
 writers. 
 
 The principal rules for Definition are three ; viz. 1st. The Definition 
 must be adequate ; i.e. neither too extensive nor too narrow for the 
 thino- defined: e.g. to define "fish," "an animal that lives in the 
 water," would be too extensive, because manymsects, <fec,, live m the 
 water; to define it, "an animal that has an air-bladder," would be 
 too 7iarrow; because many fish are without any. 
 
 2d. The Definition must be in itself plainer than the thing defined, 
 else it would not explain it: I say, "in itself," [i.e. generally,) 
 because, to some particular person, the term defined may happen to 
 be even more familiar and better understood, than the terms of the 
 definition. 
 
 3d. It must be couched in a convenient number of appropriate 
 words, (if such can be found suitable for the purpose:) for figurative 
 words (which are opposed to appropriate) are apt to produce ambi- 
 guity or indistinctness: too great brevity may occasion obscurity; and 
 too great 2^'i^olixity, confusion. 
 
CHAPTER II. 
 
 OF PROPOSITIONS. 
 
 § 1. The second part of Logic treats of tlie Proposition; which is, 
 ^'Judgment expressed in words.'' 
 
 A proposition is defined logically "« sentence indicative,'" i.e. 
 affirming or denying ; (this excludes commands and questions.) " Sen- 
 tence " being the Genus, and "indicative" the Difference, this defini- 
 tion expresses the whole essence ; and it relates entirely to the words 
 of a Proposition. With regard to the matter, its Property is to be true 
 OY false, and therefore it must not be ambiguous, (for that which has 
 more tlian one meaning, is in reality several Propositions ;) nor imp)er- 
 fect, nor ungrammatical, for such an expression has no meaning at all. 
 
 Since the Substance [i.e. Genus, or material part) of a Proposition is, 
 tliat it is a sentence; and since every sentence (whether it be a Proposi- 
 tion or not) may be expressed either absolutely, (as '* Csesar deserved 
 death;" "did Caesar deserve death'?") or under an hypothesis (as, "if 
 Caesar was a tyrant, what did he deserve?" " Was Ctesar a hero or a 
 villain?" "If Csesar was a tyrant, he deserved death;" "he was 
 either a hero or a villain,") on this we found the division of Proposi- 
 tions according to their substance; viz. into categorical and hypotheticcd. 
 And as Genus is said to be predicated in. .quid, (what,) it is by the 
 members of this division that we answer the question, icltcit is this 
 Proposition? {quce est propositio.) Answer, categorical or hypothetical. 
 
 Categorical Propositions are subdivided into pure, which asserts 
 simply or purely, that the subject docs or does not agree with the 
 predicate, and modal, which expresses in what mode (or manner) it 
 agrees; e.g. "an intemperate man will be sickly;" " Brutus killed 
 Csesar;" are jowre. " An intemperate man ^sSS\. probahly be sickly;" 
 " Brutus killed Cadsar justly ;'' are modal. At present we speak only 
 of pure categorical Propositions. 
 
 It being the Differentia of a Proposition, tlmt it affrms or denies, 
 and its Property to be true or false; and Difi*erentia being predicated 
 in quale quid; Property in cpmle, avc hence form another division of 
 Propositions, viz. according to their quality, into affirmative, and nega- 
 tive, (which is the cpiality of the expression, and therefore (in Logic) 
 essential;) and into true and false, (which is the quality of the matter, 
 and therefore accidental.) An affirmative Proj^osition is one whose 
 Copula is affirmative, as "birds fly;" "not to advance is to go 
 back;" a negative proposition is one whose Copula is negative, as 
 "man is not perfect ;" no " miser is happy." 
 
Chap. II.] OF PROPOSITIONS. 33 
 
 Anotlier division of Propositions is according to their quantity, (or 
 extent ;) If the Predicate Is said of the v-liole of the Subject, the Pro- 
 position is universal; If of a _29a?'^ of It only, the Proposition Is ixirli- 
 cular, (or partial;) e.g. "England Is an Island;" "all tyrants are 
 miserable;" "no miser is rich;" are universal Propositions, and 
 their Subjects are therefore said to be distributed, being understood 
 to stand, each, for the lohole oi its significates : but, '■'some Islands 
 are fertile;" "all tyrants are not assassinated;" are 2yarticidar, and 
 their Subjects, consequently not distributed, being taken to stand for 
 a part only of their significates. 
 
 As every Proposition must be either affirmative or negative, and 
 must also be either universal or particular, we reckon In all, four kinds 
 of pure categorical Propositions, [i.e. considered as to their quantity 
 and quality both;) viz. universal affirmative, whose symbol (used for 
 brevity,) Is A; miiversal negative, E; j)articidar affirmative, /; 
 particular negative 0. 
 
 §1 2. When the subject of a Proposition is a common Term, the 
 universal signs ("all, no, every,") are used to indicate that It is 
 distributed, (and the Proposition consequently Is universal ;) the 
 imrticular signs, ("some, (kc") the contrary; should there be no sign 
 at all to the common Term, the quantity of the Proposition (which Is 
 called an indefinite Proposition) Is ascertained by the mailer; i.e. the 
 nature of the connection between the extremes ; which is either 
 necessary, impossible, or contingent. In necessary and In impossible 
 matter, an Indefinite Is understood as a universal: e.g. " birds have 
 wings;" i.e. all: " birds are not quadrupeds ;" ^.e. none: in contin- 
 gent matter, [i.e. where the terms parti}'' {i.e. sometimes) agree, and 
 partly not,) an indefinite Is understood as a particular; e.g. "food is 
 necessary to life;" "birds sing;" i.e. some do; "birds are not 
 carnivorous;" i.e. ''some are not," or, "all are not." 
 
 As for singular Propositions, {viz. those whose Subject is cither a 
 proper name, or a common Term with a singidar sign,) they are 
 reckoned as universals, (sec Ch. IV. §2,) because in them we speak of 
 the Vjliole of the subject: e.g. when we say, "Brutus was a Roman," 
 we mean the lolwle of Brutus : this Is the general rule ; but some 
 singular Propositions may fairly be reckoned ixtrticular; i.e. when 
 some qualifying word Is Inserted, which indicates that you arc not 
 speaking of the lohole of the subject; e.g. " Cajsar was not ivholl// 
 a tyrant;" "this man is occasionally intemperate;" " non omnis 
 rnoriar.'" It is evident that the Subject is distributed in every universal 
 Proposition, and never In a particular; (that being the very ditferenc-c 
 between universal and particular Propositions;) but the distribution 
 or non-distribution of the Predicate, depends (not on the quantify, but) 
 on the quality, of the Proposition ; for, If any 2)art of the Predicate 
 agrees with the Subject, it must be affirmed and not dcnieil of tho 
 Subject ; therefore, for an affirmative Proposition to be true, it is 
 
 D 
 
34 OF PROPOSITIONS. [Chap. II. 
 
 siiffiderit that some ^:»ar^. of the Predicate agree with the subject ; and 
 (for the same reason) for a negative to be true, it is necessary that 
 the lulwle of the Predicate should disagree with the Subject : e.g. it is 
 true that "learning is useful," though the whole of the Term "use- 
 ful " does not agree with the Term " learning," (for many things are 
 useful besides learning,) but "no vice is useful," would be false, if 
 any part of the Term " useful " agreed Avith the Term " vice ;" [i.e. 
 if you could find any one useful thing which was a vice.) The two 
 practical rules then to be observed respecting distribution, are, 
 
 1st. All universal Propositions (and no particular) distribute the 
 Subject. 
 
 2d. All negative, (and no affirmative) the Predicate. 
 
 It may Jiaioiden indeed, that the whole of the Predicate in an affir- 
 mative may agree with the Subject; e.g. it is equally true, that "all 
 men are rational animals ;" and " all rational animals are men:" but 
 this is merely accidental, and is not at all implied in the form of 
 exjyression, which alone is regarded in Logic. 
 
 Of Opposition. 
 
 § 3. Two Propositions are said to be opposed to each other, Avhen, 
 having the same Subject and Predicate, they diff"er in quantity, or 
 quality, or both. It is evident, that with any given Subject and 
 Predicate, you may state four distinct Propositions, viz. A, E, I, and 
 ; and any two of these are said to be ojjjjosed; hence there are four 
 different kinds of opposition, viz. 1st. the two universals, (A and E) 
 are called contraries to each other; 2d. the two particular, (I and 0,) 
 subcontraries ; 3d. A and I, or E and 0, subalterns; 4th. A and 0, 
 or E and I, contradictories. As it is evident that the truth or falsity 
 of any Proposition (its quantity and quality being known,) must depend 
 on the matter of it, we must bear in mind that, "m necessary matter 
 all affirmatives are true, and negatives false ; in i7npossible matter, vice 
 versa; in contingent matter, all universals false, and particidars true;" 
 {e.g. ''all islands, (or, some islands,) are surrounded by water," must 
 be true, because the matter is necessary: to say, ''no islands, or some 
 — not, (fee." would have been false ; again, " some islands are fertile ;" 
 " some are not fertile," are both true, because it is contingent matter : 
 put " alV or " no " instead of " some,'' and the propositions will be 
 false.) Hence it will be evident, that contraries will be both false in 
 contingent matter, but never both true: subcontraries, both true in 
 contingent matter, but never both false: contradictories, always one 
 true and the other false, <fec. with other observations, which will be 
 immediately made on viewing the scheme ; in which the four Pro- 
 positions are denoted by their symbols ; the different kinds of 
 matter, by the initials n, i, c, and the truth or falsity of each Pro- 
 position in each matter, by the letter v. for [verum) true, f. for 
 [falsum] false. 
 
Chap. II.] 
 
 OF PROPOSITIONS. 
 
 35 
 
 n. V. 
 i. f. 
 c. f. 
 
 n. V. 
 i. f. 
 c. V. 
 
 f. n. 
 V. i. 
 f. c. 
 
 f. n. 
 V. i. 
 V. c. 
 
 Bj a careful study of this sclieme, bearing in mind, and applying 
 the above rule concerning matter, the learner will easily elicit all the 
 maxims relating to Opposition ; as that, in the subalterns, the truth of 
 the particular (which is called the subalternat/,) follows from the truth 
 of the universal {subaUernans) and the falsity of the universal from 
 the falsity of the particular: that subalterns differ in quantity alone; 
 contraries, and also subcontraries in qualitu alone; contradictories, in 
 both: and hence, that if any Proposition is known to be true, we infer 
 that its contradictory is false ; if false, its contradictory true, <fec. 
 
 Of Conversion. 
 § 4. A Proposition is said to be converted when its Terms are 
 transposed: when nothing more is done, this is called simple Conver- 
 sion. No Conversion is of any use, unless it be iUative: i.e. when the 
 truth of the converse follows from the truth of the exposita, (or propo- 
 sition givea ;) e.g. 
 
 '* No virtuous man is a rebel, iJierefore 
 No rebel is a virtuous man." 
 
 ** Some boasters arc cowards, therefore 
 Some cowards are boasters." 
 
 Conversion can then only be illative wlien no Term is distributed in 
 the converse, which was not distributed in the exposita: (for if tliat be 
 done, you will employ a Term universalis/ in the converse, whidi was 
 only used partiaUj/ in the exposita.) Hence, as E distributes both 
 Terms, and I neither, these Propositions may be illatively converted 
 in the simple manner; (vid. Rule 2.) But as A does not distribute 
 
36 OF PROPOSITIONS. [Chap. II. 
 
 the Predicate, its simple Conversion would not be illative ; {e.g. from 
 " all birds are animals," you cannot infer that "all animals are birds,") 
 as there would be a Term distributed in the converse, which was not 
 before. We must therefore limit its quantity from universal to partic- 
 ular, and the Conversion will be illative: [e.g. "some animals are 
 birds:") this might be fairly named Conversion by limitation; but is 
 commonly called " Conversion ]jer accidens.'" E may thus be con- 
 verted also. But in 0, whether the quantity be changed or not, there 
 will still be a Term (the Predicate of the converse) distributed, which 
 was not before : you can therefore only convert it by changing the 
 quality ; i.e. considering the negative as attached to the Predicate 
 instead of to the Copida, and thus regarding it as I. One of the Terms 
 will then not be the same as before ; but the Proposition will be 
 ^equipollent ; [i.e. convey the same meaning,) e.g. " some members of 
 the University are not learned:" you may consider " not learned " as 
 the Predicate, instead of "learned;'' the Proposition will then be I, 
 and of course may be simply converted, " some who are not learned 
 are members of the University." This may be named Conversion by 
 negation ; or as it is commonly called, by contra-position. A may 
 also be fairly converted in this way, e.g. 
 
 " Every poet is a man of genius ; therefore 
 He who is not a man of genius, is not a poet:" 
 (or, " None but a man of genius can be a poet.") 
 
 For (since it is the same thing, to affinn some Attribute of the Sub- 
 ject, or to deny the absence of that Attribute,) the original Proposition 
 is precisely sequipoUent to this, 
 
 subj. pred. 
 
 " No poet is not a man of genius ; 
 
 which, being E, may of course be simply converted. Thus, in one of 
 these three ways, every Proposition may be illatively converted : viz. 
 " E, /, simply; A, 0, by ^legation; A, E, limitation." Note, that as 
 it was remarked, that in some affirmatives, the whole of the Predicate 
 does actually agree with the Subject ; so, when this is the case, A 
 may be illatively converted, simply ; but this is an accidental circum- 
 stance. In a just definition, this is always the case ; for there the 
 terms being exactly equivalent, (or, as they are called, convertibh 
 Terms,) it is no matter which is made the Subject, and which the 
 Predicate, e.g. "a good government is that which has the happiness 
 of the governed for its object;" if this be a right definition, it will 
 follow that *' a government which has the happiness of the governed 
 for its object, is a good one." Most Propositions in Mathematics are 
 of this description : e.g. 
 
 " All equilateral triangles are equiangular;" and 
 " All equiangular triangles are equilateral." 
 
CHAPTER III. 
 
 OF ARGUMENTS. 
 
 § 1. The third operation of the mind, viz. Eeasoning (or discourse) 
 expressed in words, is Argument; and an Argument stated at full 
 length, and in its regular form is called a Syllogism: the third part of 
 Logic therefore treats of the Syllogism. Every Argument consists of 
 two parts ; that which is to be 2^^'oved ; and that by means of ivhich it 
 is proved : the former is called before it is proved the Question ; ichen 
 jjroved, the Conclusion, (or inference;) that which is used to prove it, 
 if stated last, (as is often done in common discourse,) is called the 
 Reason, and is introduced by " because," or some other causal conjunc- 
 tion ; {e.g. " Caesar deserved death, because he was a tyrant, and all 
 tyrants deserve death.") If the Conclusion he stated last, (which is 
 the strict logical form, to which all reasoning may he reduced,) then 
 that which is employed to prove it is called the Premises; and the 
 Conclusion is then introduced by some illative conjunction, as " there- 
 fore:" e.g. 
 
 " All tyrants deserve death ; 
 Csesar was a tyrant ; 
 therefore he deserved death." 
 
 Since then an Argument is an expression in which ^\from some- 
 thing laid down and granted as true, [i.e. the Premises) something 
 else, {i.e. the Conclusion) beyond this, must be admitted to be true, 
 as following necessarily, {or resulting) from the other;" and since 
 Logic is Avholly concerned in the use of language, it follow?* that a 
 Syllogism (which is an Argument stated in a regular logical form,) 
 must be " an Argument so expressed, that the conclusiveness of it is 
 manifest from the mere force of the exjjression," i.e. without consider- 
 ing the meaning of the Terms: e.g. in this syllogism, " B is A, C is 
 B, therefore C is A:" the conclusion is inevitable, whatever Terms 
 A, B, and C, respectively, are understood to stand for. And to tliis 
 form, all legitimate Arguments may ultimately be brouglit. 
 
 § 2. The rule or axiom, (commonly called *' dictum de omni ct 
 nullo,") by which Aristotle proves the validity of this Argument is 
 this: "■ iL'hatever is j^^'cdicated of a Term distributed, whether affir- 
 matively or negatively, may be ]wedicated> in like manner, of every tiling 
 contained under it." Thus, in the examples above, A is predicated 
 of B distributed, and C is contained under B, {i.e. is its Subject ;) 
 
38 OF ARGUMENTS. [Chap. III. 
 
 therefore A is predicated of C: so "all tyrants, &c." (p. 37.) This 
 rule may be ultimately applied to all Arguments ; (and their validity 
 ultimately rests on their conformity thereto;) but it cannot be 
 directly and immediately applied to all, even of pure categorical Syllo- 
 gisms ; for the sake of brevity therefore some other axioms are com- 
 monly applied in practice, to avoid the occasional tediousness of reduc- 
 ing all Syllogisms to that form in Avhich Aristotle's dictum is applicable. 
 
 We will speak first of pure categorical Syllogisms ; and the axioms 
 or canons by which their validity is to be proved : viz. first, if two 
 Terms agree ivith one and the same third, they agree loith each other : 
 second, if one Term agrees and another disagrees with one and the 
 same third, these two disagree with each other. On the former of these 
 canons rests the validity of affirmative conclusions ; on the latter, of 
 negative : for no Syllogism can be faulty which does not violate these 
 canons ; none correct which does : hence on these two canons are 
 built the rules or cautions which are to be observed with respect to 
 Syllogisms, for the purpose of ascertaining whether those canons have 
 been strictly observed or not. 
 
 1st. Every Syllogism has three, and only three Terms; viz. the two 
 Terms (or extremes, as they are commonly called) of the Conclusion, 
 (or question;) (whereof first, the Subject is called the minor Term; 
 second, the Predicate, the major ;) and third, the middle Term, with 
 which each of them is separately compared, in order to judge of their 
 agreement or disagreement with each other. If therefore there were 
 two middle terms, the extremes, {or Terms of the Conclusion) not being 
 both compared to the same, could not be compared to each other. 
 
 2d. Every Syllogism has three, and only three Propositions ; viz. 
 first, the major Premiss, (in which the major Term is compared with 
 the middle;) second, the mmor Premiss, (in which the minor Term is 
 compared with the middle;) and third, the Conclusion, in which the 
 minor Term is compared with the major. 
 
 3d. Note, that if the middle Term is ambiguous, there are in reality 
 two middle Terms, in sense, though but one in sound. An ambiguous 
 middle Term is either an equivocal Term, used in different senses in 
 the two Premises ; [e.g. 
 
 " Light is contrary to darkness; 
 Feathers are light ; therefore 
 Feathers are contrary to darkness.") 
 
 Or a Term not distributed ; for as it is then used to stand for a 
 Y>aH only of its signification, it may happen that one of the extremes 
 may have been compared with one part of it, and the other, with 
 another part of it ; e.g. 
 
 " White is a colour. 
 Black is a colour ; therefore 
 Black is white." — Again, 
 
Chap. III.] OF ARGUMENTS. 39 
 
 " Some animals are beasts, 
 Some animals are birds ; therefore 
 Some birds are beasts." 
 
 Tlie middle Term therefore must he distributed once, at least, in tlie 
 Premises ; {I.e. by being the subject of an universal, or Predicate of 
 a negative, Ch. II. § 2. p. 33.) and once is sufficient; since if one 
 extreme has been compared to a part of the middle Term, and 
 another to the ivhole of it, they must have been both compared to the 
 same. 
 
 4th. No Term must he distributed in the Conclusion winch was not 
 distributed in one of the preinises ; for that (it is called an illicit process, 
 either of the major or the minor Term) would be to employ the ivhole 
 of a Term in the Conclusion, when you had employed only a j^ctrt of it 
 in the Premiss ; and thus, m reality, to introduce a fourth Term ; e.g. 
 
 " All quadrupeds are animals, 
 A bird is not a quadruped ; therefore 
 It is not an animal." — Illicit process of the major. 
 
 5tli. Fro7n negative Premises you can infer nothing. For in them 
 the middle is pronounced to disagree loith both extremes ; not to agree 
 with both; or to agree with one, and disagree with the other ; there- 
 fore they cannot be compared together ; e.g. 
 
 " A fish is not a quadruped," 
 
 *' A bird is not a quadruped," proves nothing. 
 
 6th. If one Premiss be negative, the conclusion must be negative ; 
 for in that Premiss the middle Term is pronounced to disagree with 
 one of the extremes, and in the other Premiss, (Avhich of course is 
 affirmative, by the preceding rule) to agree with the other extreme ; 
 therefore the extremes disagreeing with each other, the conclusion is 
 negative. In the same manner it may be shown, that to 2^'f^ove a 
 negative conclusion one of the Premises must be a negative. 
 
 By these six rules, all syllogisms are to be tried ; and from them 
 it will be evident, first, that nothing can be j^roved from two particular 
 Premises ; (for you will then have either the middle Term undistributed, 
 or an illicit process; e.g. 
 
 '* Some animals are sagacious; 
 Some beasts are not sagacious ; 
 Some beasts are not animals.") 
 
 And for the same reason, secondly, that if one of the Premises bo 
 particular, the Conclusion must be particidar ; e.g. from 
 
 " All who fight bravely deserve reward; 
 Some soldiers fight bravely ; ' ' 
 
 you can only infer that some soldiers deserve reward. 
 
40 OF ARGUMENTS. [Chap. III. 
 
 For to infer a universal Conclusion, would be an illicit process of 
 the minor. But from two universal Premises you cannot always infer 
 a universal Conclusion ; e.g. 
 
 " All gold ia precious, 
 All gold is a mineral ; therefore 
 Some mineral is precious." 
 
 And even when we can infer a universal, we are always at liberty 
 to infer a particular ; since what is predicated of all may of course he 
 predicated of some. 
 
 Of Moods. 
 
 § 3. When we designate the three Propositions of a Syllogism in 
 their order, according to their respective quantity and quality, {i.e. 
 their symbols) we are said to determine the Mood of the Syllogism ; 
 e.g. the example just above, *' all gold, (fcc." is in the Mood A, A, I. 
 As there are four kinds of Propositions, and three Propositions in each 
 Syllogism, all the possible ways of combining these four, (A,E,I,0,) 
 by threes, are sixty-four. For any one of these four may be the 
 major Premiss ; each of these four majors may have four different 
 minors, and of these sixteen pairs of Premises, each may have four 
 different Conclusions. 4 X 4 ( ^= 16) X 4 .z= 64. This is a mere arith- 
 metical calculation of the moods, without any regard to the Logical 
 rules : for many of these Moods are inadmissible in practice, from 
 violating some of those rules ; e.g. the Mood E,E,E, must be rejected, 
 as having negative Premises; 1,0,0, for jmr^^'ci^/ar Premises; and 
 many others for the same faults. By examination then of all, it will 
 be found that of the sixty-four, there remain but twelve Moods, which 
 can be used in a legitimate S^^logism, viz. A, A, A, A, A, I, A, E, E, 
 A, E, 0, A, I, I, A, 0, 0, E, A, E, E, A, 0, E, I, 0, I, A, I, 
 I, E, 0, 0, A, 0. 
 
 Of Figure. 
 
 5 4. The Fia'ure of a Svlloo-ism consists in the situation of the 
 middle Term with respect to the extremes of tlie conclusion, ((i.e. the 
 major and minor term.) When the middle Term is made the subject of 
 the major Premiss, and the Predicate of the minor, that is called the 
 first Figure ; (which is far the most natural and clear of all, as to this 
 alone. Aristotle's dictum may be at once applied.) In the second 
 Figure the middle Term is the predicate of both Premises : in the 
 third, the Subject of both : in the fourth, the Predicate of the major 
 Premiss, and the Subject of the minor. (This is the most awkward 
 and unnatural of all, being the very reverse of the first.) Note, that 
 the j9roj:>e?' o?T/6r is to place the major Premiss ^?'S^, and the minor 
 second; but this does not constitute the major and minor Premises ; 
 for that Premiss (Avherever placed) is the major which contains tJie 
 
Chap. III.] OF ARGUMENTS. 41 
 
 major Term, and the minor, the minor, (vid. R. 2. p. 38.) Each of 
 the allowable Moods mentioned above, will not be allowable in every 
 Figure ; since it may violate some of the foregoing rules, in one 
 Figure, though not in another: e.g. I, A, I, is an allowable Mood in 
 the third Figure ; but in the first, it Avould have an umlisirihuted 
 middle. So A,E,E, would in the first figure have an illicit process 
 of the onajor, but is allowable in the second ; and A, A, A, which in 
 the first Figure is allowable, would in the third have an illicit process 
 of the minor: all which maybe ascertained by trying the different 
 Moods in each Figure, as per scheme. 
 
 Let A represent the major Term, C the minor, B the middle. 
 
 1st Fig. 
 
 2d Fig. 
 
 3d Fig. 
 
 4th Fig. 
 
 B, A, 
 
 A, B, 
 
 B, A, 
 
 A, B, 
 
 C, B, 
 
 C, B, 
 
 B, C, 
 
 B, C, 
 
 C, A, 
 
 C, A, 
 
 C, A, 
 
 C, A. 
 
 The Terms alone being here stated, the quantity and quality of 
 each Proposition (and consequently the Mood of the whole Syllogism) 
 is left to be filled up : [i.e. between B, and A, I may place either a 
 negative or aflirmative Copula ; and I may prefix either a universal 
 ov p)articular sign to B.) By applying the Moods then to each Figure, 
 it will be found that each Figure will admit six Moods only, as not 
 violating the rules against undistributed middle, and against illicit 
 jjrocess : and of the Moods so admitted, several (though valid) are 
 useless, as having a particular Conclusion, Avhen a universal might 
 have been drawn ; e.g. A, A, I, in the first Figure, 
 
 " All human creatures are entitled to liberty ; 
 All slaves are human creatures ; therefore 
 Some slaves are entitled to liberty." 
 
 Of the twenty-four IMoods then (six in each Figure) five are for this 
 reason neglected : for the remaining nineteen, Logicians have devised 
 names to distinguish both the Mood itself, and the figure in which it 
 is found ; since when one Mood {i.e. one in itself, without regard to 
 Figure) occurs in two different Figures, (as E,A,E, in the first and 
 second) the mere letters denoting the Mood would not inform us con- 
 cerning the Figure. In these names then, the three rowels denote 
 the Propositions of which the Syllogism is composed ; the consonants 
 (besides their other uses, of which hereafter) serve to keep in mind 
 the Figure of the Syllogism. 
 
 Fig. 1. bArbArA, cElArEnt, dArIT, fErlOque prions. 
 Fig. 2. cEsArE, cAmEstrEs, fEstInO, bArOkO, sccundre. 
 Fin- 3 /tt'rtia, dArAptI, dIsAmIs, dAtlsI, fElAptOn, bOkArdO, 
 
 °* ' \fErIsO, habet: qnnrta insuper addit. 
 Fig. 4. brAniAntlp, cAmEnEs, dImArls, fElApO, frEsIsOu. 
 
42 OF ARGUMENTS. [Chap. III. 
 
 By a careful study of these mnemonic lines (which must be com- 
 mitted to memory) you will perceive that A can only be proved in the 
 first Figure, in which also every other proposition may be proved ; 
 that the second proves only negatives; the third only jJar^^CMZa?^s, he, 
 with many other such observations, which will readily be made, (on 
 trial of several Syllogisms, in difi'erent Moods) and the reasons for 
 which will be found in the foregoing rules. E.G. To show why the 
 second Figure has only negative Conclusions, we have only to consider, 
 that in it the middle Term being the Predicate in both Premises, would 
 not be distributed unless one Premiss were negative; (vid. R. 2. p. 28.) 
 therefore the conclusion must be negative also, by R. 6. p. 39. 
 One Mood in each Figure may suffice in this place by way of example ; 
 first, Barbara, viz. (bAr.) 
 
 Every B is A ; (bA) every C is B ; therefore (rA) every C is A, 
 e.g. let the major Term (which is represented by A) be " one who 
 possesses all virtue;" the minor term (C) " every man who possesses 
 one virtue;" and the middle term (B) ''every one who possesses 
 prudence;" and you will have the celebrated argument of Aristotle, 
 Eth. sixth book, to prove that the virtues are inseparable ; viz. 
 
 " He who possesses prudence, possesses all virtue; 
 
 He who possesses one virtue, must possess prudence ; therefore 
 He who possesses one, possesses all." 
 
 Second, Camestrcs, (cAm) every A is B ; (Es) no C is B ; (trEs) no 
 C is A. Let the major term (A) be " true philosophers," the minor 
 (C) "the Epicureans;" the middle (B) "reckoning virtue a good in 
 itself;" and this will be part of the reasoning of Cicero, Off. book 
 first and third, against the Epicureans. Third, Darapti, viz. (dA) 
 every B is A; (rAp) every B is C; therefore (tl,) some C is A: e.g. 
 
 " Prudence has for its object the benefit of individuals; 
 But prudence is a virtue ; therefore 
 Some virtue has for its object the benefit of the individual," 
 
 is part of Adam Smith's reasoning, {Moral Sentiments,) against Hut- 
 cheson and others, who placed all virtue in benevolence. Fourth, 
 Camenes, viz. (cAm) every A is B ; (En,) no B is C ; therefore (Es,) 
 no C is A : e.g. 
 
 " Whatever is expedient, is conformable to nature; 
 
 Whatever is conformable to nature, is not hurtful to society; therefore 
 What is hurtful to society is never expedient," 
 
 is part of Cicero's argument in Of. third book: but it is an inverted 
 and clumsy way of stating what would much more naturally fall into 
 the first Figure ; for if you examine the propositions of a Syllogism 
 in the fourth Figure, beginning at the Conclusion, you wiU see that as 
 the major Term is predicated of the minor, so is the minor of the 
 
Chap. III.] OF ARGUMENTS. 43 
 
 middle, and tliat again of the major : so that the major appears to be 
 merely 2^^^C'dicated of itself. Hence the five Moods in this Figure are 
 seldom or never used ; some one of the fourteen {Moods icitli riames) 
 in the first three Figures, being the forms into which all Arguments 
 may most readily be thrown ; but of these, the four in the first Figure 
 are the clearest and most natural; as to them, Aristotle's dictum will 
 immediately apply. And as it is on this dictum that all Reasoning 
 idtlmately depends, so all Arguments may be somehow or other brought 
 into some one of these four Moods ; and a Syllogism is, in that case, 
 said to be reduced: {i.e. to the first Figure.) These four are called 
 the perfect Moods, and all the rest, imjjerfect. 
 
 OsTEXSiYE Reduction. 
 
 § 5. In reducing a Syllogism, we are not of course allowed to intro- 
 duce any new Term or Proposition, having nothing granted but the 
 truth of the Premises ; but these Premises are allowed to be illatively 
 converted, (because the truth of any Proposition imiMes that of its 
 illative converse) or transposed: by taking advantage of this liberty, 
 where there is need, we deduce in Figure one, from the Premises 
 originally given, either the rery same Conclusion as the original one, 
 or another from which the original Conclusion follows, by illative 
 Conversion; e.g. Darapti. 
 
 *' All wits are dreaded; 
 All wits are admired ; 
 Some who are admired are dreaded." 
 
 Into Daril, by converting by limitation {per accidens) the minor Pre- 
 miss. 
 
 " All wits are dreaded; 
 
 Some who are admired are wits ; therefore 
 Some who are admired are dreaded." 
 
 Camestres. 
 
 " All true philosophers account virtue a good in itself; 
 The advocates of pleasure do not account, &c. 
 Therefore they are not true philosophers." 
 
 Reduced to Celarent, by simply converting the minor, and then trans- 
 posing the Premises. 
 
 " Those who account virtue a good in itself, are not advocates 
 of pleasure ; 
 All true philosophers account virtue, 6ic.\ therefore 
 No true philosophers are advocates of pleasure." 
 
 This Conclusion may be illatively converted into the original one. 
 
44 OF ARGUMENTS. [Chap. III. 
 
 Baroho, e.g. 
 
 " Every true patriot is a friend to religion; 
 
 Some great statesmen are not friends to religion ; 
 Some great statesmen are not true patriots." 
 
 To Ferio, by converting the major by negation (contraposition) vide 
 Ch. II. § 4. 
 
 " He who is not a friend to religion, is not a true patriot ; 
 Some great statesmen, &c.," 
 
 and the rest of the Syllogism remains the same ; only that the minor 
 Premiss must be considered as affirmative, because you take *'not a 
 friend to religion " as the middle Term. In the same vcid^rmtv Bokardo 
 to Daril; e.g. 
 
 ** Some slaves are not discontented ; 
 All slaves are wronged ; therefore 
 Some who are wronged are not discontented." 
 
 Convert the major by negation, (contraposition) and then transpose 
 them ; the Conclusion will be the converse hy negation of the original 
 one, which therefore may be inferred from it ; e.g. 
 
 ** All slaves are wronged; 
 
 Some who are not discontented are slaves ; 
 Some who are not discontented are wrono;ed." 
 
 In these ways (which are called Ostensive Reduction, because you 
 prove in the first Figure, either the very same conclusion as before, or 
 one which implies it) all the imperfect Moods may be reduced to the 
 four perfect ones. But there is also another way, called reductio ad 
 impossibile, 
 
 § 6. By which we prove (in the first Figure) not directly that the 
 original Conclusion is true, but that it cannot he false; i.e. that an 
 absurdity would follow from the supposition of its being false, e.g. 
 
 *' All true patriots are friends to religion; 
 
 Some great statesmen are not friends to religion ; 
 Some great statesmen are not true patriots." 
 
 If this conclusion be not true, its contradictory must be true ; viz. 
 
 " All great statesmen are true patriots." 
 
 Let this then be assumed, in the place of the minor Premiss of the 
 original Syllogism, and a false Conclusion will be proved ; e.g. bAr. 
 
 ' ' All true patriots are friends to religion ; 
 bA, All great statesmen are true patriots ; 
 rA, All great statesmen are friends to religion:'''' - 
 
Chap. III.] OP ARGUMENTS. 45 
 
 for as this Conclusion is the contradictory of the original minor Pre- 
 miss, it must he false, since the premises arc always supposed to he 
 granted ; therefore one of the Premises (hy which it lias been correctly 
 proved) must be false also ; but the major Premiss (being one of those 
 originally granted) is true; therefore the falsity must he in the minor 
 Premiss; which is the contradictory of the original Conclusion; there- 
 fore the original Conclusion must be true. This is the indirect mode 
 of Reasoning. 
 
 § 7. This kind of Reduction is seldom employed but for Baroko and 
 Bokardo, which are thus reduced by those who confine themselves to 
 simple Conversion, and Conversion by limitation, [per accidens;) and 
 they framed the names of their Moods with a view to point out the 
 manner in which each is to be reduced; viz. B, C, D, F, which are 
 the initial letters of all the Moods, indicate to which Mood of the first 
 Figure, {Barbara, Celarent, Darii, and Ferio,) each of the others is 
 to be reduced: m, indicates that the Premises are to be transp)osed; 
 s, and p, that the Proposition denoted by the vowel immediately pre- 
 ceding, is to be converted; s, simply, ]?, p>er accidens, (by limitation:) 
 thus, in Camestres, (see example, p. 42,) the C, indicates that it must 
 be reduced to Celarent; the two ss, that the minor Premiss and Con- 
 clusion must be converted simply; the m, that the Premises must be 
 transposed. K, (which indicates the reduction ad, imposslbile) is a 
 sign that the Proposition denoted by the vowel immediately before it, 
 must be left out, and the contradictory of the Conclusion substituted; 
 viz. for the minor Premiss in Baroko, and the major in Bokardo. 
 But it has been already shown, that the Conversion by contraposition, 
 (by negation,) will enable us to reduce these two Moods, ostensively. 
 
CHAPTER IV. 
 
 OF MODAL SYLLOGISMS, AND OF ALL ARGUMENTS BESIDES 
 REGULAR AND PURE CATEGORICAL SYLLOGISMS. 
 
 Of Modals. 
 
 § 1. Hitherto we have treated of ^^wre categorical Propositions, 
 and the Syllogisms composed of such : a Modal Proposition may be 
 stated as a 2^ure one, by attaching the Mode to one of the Terms; and 
 the Proposition will in all respects fall imder the foregoing rules ; e.g. 
 " John killed Thomas wilfully and maliciously;''^ here the mode is to 
 be regarded as part of the Predicate. " It is 2^i^ohable that all know- 
 ledge is useful;" " probably useful" is here the Predicate ; but when 
 the Mode is only used to express the necessary, contingent, or im- 
 possible connection of the Terms, it may as well be attached to the 
 Subject: e.g. "man is necessarily isioviiA','^ is the same as, ''all men 
 are mortal:" and "this man is occasionally intemperate," has the 
 force of a particular: (vide Part 11. § 2. p. 33.) It is thus that two 
 singular Propositions maybe contradictories; e.g. "this man is never 
 intemperate," will be the contradictory of the foregoing. Indeed 
 every sign (of universality or particularity) may be considered as a 
 Mode. Since, however, in all Modal Propositions, you assert that the 
 dictum [i.e. the assertion itself) and the mode, agree together, or dis- 
 agree, so, in some cases, this may be the most convenient Way of 
 
 subj.cop. pred. subject. 
 
 stating a Modal, purely: e.g. "It is impossible that all men should 
 
 subject. subject, cop. 
 
 be virtuous." Such is a proposition of St. Paul's: — " This is 
 
 pred. subject. 
 
 a faithful saying, &lc. that Jesus Christ came into the world to save 
 
 subject. 
 f ^ 
 
 sinners." In these cases, one of your Terms (the Subject) is itself 
 an entire Proposition. Thus much for Modal Propositions. 
 
 Of Hypothetic als. 
 
 § 2. A hypothetical Proposition is defined to be, two or more cate- 
 goricals united by a Copula, (or conjunction ;) and the different kinds 
 
Chap. IV.] OF MODAL SYLLOGISMS. 47 
 
 of hypothetical Propositions are named from their respective conjmic- 
 tions ; viz. conditional, disjunctive, causal, Arc. 
 
 When a hypothetical Conclusion is inferred from a hj-pothetical 
 Premiss, so that the force of the Reasoning does not turn on the 
 hypothesis, then the h>^othesis (as in Modals) must be considered as 
 part of one of the Terms; so that the Reasoning will he, in effect, 
 categorical: e.g. 
 
 predicate. 
 
 " Every conqueror is either a hero or a villain : 
 Caesar was a conqueror ; therefore 
 
 predicate. 
 ^ 1 ; ^ 
 
 He was either a hero or a villain.^' 
 " Whatever comes from God is entitled to reverence; 
 
 subject. 
 
 ^ ■ N 
 
 If the Scriptures are not wholly false, they must come from God ; 
 If they are not wholly false, they are entitled to reverence." 
 
 But when the Reasoning itself rests on the hypothesis, (in which 
 way a categorical Conclusion may he draAvn from a hypothetical Pre- 
 miss,) this is what is called a hypothetical Syllogism; and rules have 
 been devised for ascertaining the validity of such Arguments, at once, 
 without bringing them into the categorical form. (And note, tliat in 
 these Syllogisms the hyp>othetical Premiss is called the major, and the 
 categorical one, the minor.) They are of two kinds, conditional and 
 disjunctive. 
 
 Of Conditionals. 
 
 § 3. A Conditional Proposition has in it an illative force; i.e. it 
 contains two, and only two categorical Propositions, whereof one 
 results from the other, (or, follows from it,) e.g. 
 
 antecedent. 
 
 " If the Scriptures are not wholly false, 
 
 consequent. 
 
 '' T ^ 
 
 they are entitled to respect." 
 
 That from which the other results, is called the antecedent; that which 
 results from it, the consequent, {consequens ;) and the connection 
 between the two, (expressed by the word **if") the consequence, 
 {consequentia.) The natural order is, that the antecedent should come 
 before the consequent; but this is frequently reversed: e.g. "the 
 husbandman is well off if he knows his own advantages ;" Virg. Gear. 
 And note, that the truth or falsity of a conditional Proposition depends 
 entirely on the consequence: e.g. " if Logic is useless, it deserves to be 
 neglected;" here both antecedent and consequent avo false: yet the 
 
48 OF MODAL SYLLOGISMS. [Chap. IV. 
 
 whole proposition is true; i.e. it is true that the consequent ybZ/oi^s 
 from the antecedent. " If CromAvell was an Enghshman, he was an 
 usurper," is just the reverse case: for though it is true that " Crom- 
 well was an Englishman," and also that ** he was an usurper," vet it is 
 not true that the latter of these Propositions depends on the former ; 
 the whole Proposition, therefore, is false, though both antecedent and 
 consequent are true. A Conditional Proposition, in short, may he 
 considered as an assertion of the validity of a certain Argument ; since 
 to assert that an Argument is valid, is to assert that the Conclusion 
 necessarily results from the Premises, whether those Premises he true 
 or not. The meaning, then, of a Conditional Proposition is this ; that, 
 the antecedent being granted, the consequent is granted : which may be 
 considered in two points of view : first, if the antecedent he true, the 
 consequent must be true ; hence the first rule ; the antecedent being 
 granted, the consequent may be inferred : secondly, if the antecedent 
 were true, the consequent would be true ; hence the second rule ; the 
 consequent being denied, the antecedent may be denied; for the antece- 
 dent must in that case be false ; since if it were true, the consequent 
 (which is granted to be false) would be true also: e.g. "if this man 
 has a fever, he is sick ;" here, if you grant the antecedent, the first 
 rule applies, and you infer the truth of the consequent; "he has a 
 fever, therefore he is sick:" if A is B, C is D ; but A is B, therefore 
 C is D, (and this is called a constructive Conditional Syllogism ;) but 
 if you deny the consequent [i.e. grant its contradictory,) the second 
 rule applies, and you infer the contradictory of the antecedent: "he is 
 not sick, therefore he has not a fever:" this is the destructive Condi- 
 tional Syllogism: if A is B, C is D ; C is not D, therefore A is not B. 
 Again, "if the crops are not bad, corn must be cheap:" for a major; 
 then, "but the crops are not bad, therefore corn must be cheap," is 
 constructive. " Corn is not cheap, therefore the crops are bad," is 
 destructive. " If every increase of population is desirable, some 
 misery is desirable ; but no misery is desirable, therefore, some in- 
 crease of population is not desirable," is destructive. But if you 
 affirm the consequent, or deny the antecedent, you can infer nothing ; 
 for the same consequent may follow from other antecedents : e.g. in 
 the example above, a man may be ^'xckfroni other disorders besides a 
 fever ; therefore it does not follow from his being sick, that he has a 
 fever ; nor (for the same reason) from his not having a fever, that he 
 is not sick. There are, therefore, two, and only two kinds of Condi- 
 tional Syllogisms ; the constructive, founded on the first rule, and 
 answering to direct Reasoning; and the destructive, on the second, 
 answering to indirect. And note, that a conditional Proposition may 
 (like the categorical A,) be converted by negation; i.e. you may take 
 the contradictory of the consequent, as an antecedent, and the contra- 
 dictory of the antecedent, as a consequent: e.g. "if this man is not 
 sick, he has not a fever." By this conversion of the major Premiss, 
 
Chap. IY.] OF MODAL SYLLOGISMS. 49 
 
 a constructive Syllogism may be reduced to a destructive, and vice 
 versa, (See § 6. Ch. IV. p. 51.) 
 
 Of Disjunctives. 
 
 ^ 4. A disjunctive Proposition may consist of any number of cate- 
 goricals ; and, of these, some one, at least, must be true, or the whole 
 Proposition will be false : if, therefore, one or more of these categ'ori- 
 cals be denied, {i.e. granted to be false,) you may infer that the 
 remaining one, or (if several) some one of the remaining ones is true : 
 e.g. "either the earth is eternal, or the Avork of chance, or the Avork 
 of an intelligent being ; it is not eternal, nor the work of chance ; 
 therefore it is the work of an intelligent being." "It is either spring, 
 summer, autumn, or Avinter ; but it is neither spring nor summer, 
 therefore it is either autumn or Avinter." Either A is B, or C is D; 
 but A is not B, therefore C is D. Note, that in these two examples 
 (as Avell as very many others,) it is implied not only that one of the 
 members (the categorical Propositions) must be true, but that only 
 one can be true ; so that, in such cases, if one or more members be 
 affirmed, the rest may be denied; [the members may tlien be called 
 exclusive:^ e.g. "it is summer, therefore it is neither spring, autumn, 
 nor Avinter;" "either A is B, or C is D ; but A is B, therefore C is 
 not D." But this is by no means uniA^ersally the case; e.g. " virtue 
 tends to procure us either the esteem of mankind or the favour of 
 God:" here both members are true, and consequently from one being 
 affirmed, Ave are not authorized to deny the other. It is evident that 
 a disjunctive Syllogism may easily be reduced to a conditional: e.g. if 
 it is not spring or summer, it is either autumn or Avinter, &c. 
 
 The Dilemma, 
 
 ^ p. Is a complex kind of Conditional Syllogism. 
 
 1st. If you have in the major Premiss severed antecedents all Avith 
 the same consequent, then these antecedents, being (in the minor) 
 disjunctively granted, [i.e. it being granted that some one of them is 
 true,) the one common consequent may be inferred, (as in the case of 
 a simple constructi\'e syllogism:) e.g.. if A is B, C is D; and if X is 
 Y, C is D ; but either A is B, or X is Y; therefore C is D. " If the 
 blest in lieaven have no desires, they Avill bo perfectly content ; so 
 they Avill, if their desires are fully gratified ; but either they will have 
 no desires, or have them fully gratified ; therefore they will be per- 
 fectly content." Note, in this case, the two conditionals Avhich make 
 up the major Premiss may be united in one Proposition by means of 
 the Avord ''whether:'' e.g. " Avhcther the blest, kc. have no desires, 
 or haA'e their desires gratified, they Avill be content." 
 
 2d. But if the several antecedents have each a different consequent, 
 then the antecedents, being as before, disjunctively granted, you can 
 
 E 
 
50 OF MODAL SYLLOGISMS. [Chap. IV. 
 
 only disjunctively infer the consequents: e.g. if A is B, C is D; and 
 if X isY, E is F: but either A is B, or X is Y; therefore either C 
 is D, or E is F. " If ^schines joined in the public rejoicings, he 
 is inconsistent ; if he did not, he is unpatriotic ; but he either joined, 
 or not, therefore he is either inconsistent or unpatriotic." (Demost. 
 For the Crown.) This case, as well as the foregoing, is evidently 
 constructive. In the destructive form, whether you have one antece- 
 dent with several consequents, or several antecedents, either with one, 
 or with several consequents ; in all these cases, if you deny the whole 
 of the consequent or consequents, you may ui the conclusion, deny the 
 irhole of the antecedent or antecedents: e.g. " if this fact be true, 
 it must be recorded either in Herodotus, Thucydides, or Xenophon : 
 it is not recorded in any of the three, therefore it is not true." " If 
 the world existed from eternity, there would be records prior to the 
 Mosaic ; and if it Avere produced by chance, it would not bear marks 
 of design: there are no records prior to the Mosaic; and the world 
 does bear marks of design ; therefore it neither existed from eternity, 
 nor is the work of chance." These are commonly called Dilemmas, 
 but hardly differ from simple conditional Syllogisms. Nor is the case 
 different if you have one antecedent with several consequents, which 
 consequents you disjunctively deny; for that comes to the same thing 
 as wholly denying them ; since if they be not all true, the one antece- 
 dent must equally fall to the ground ; and the Syllogism will be equally 
 simple: e.g. " if we are at peace with France by virtue of the treaty 
 of Paris, we must acknowledge the sovereignty of Buonaparte ; and 
 also we must acknowledge that of Louis : but we cannot do both of 
 these ; therefore we are not at peace," &c.; which is evidently a plain 
 destructive. The true dilemma is, "a conditional Syllogism with several 
 antecedents in tlie major, and a disjunctive minor;'" hence, 
 
 3d. That is most properly called a destructive Dilemma, which has 
 (like the constructive ones) a disjunctive minor Premiss : i.e. wherf you 
 have several antecedents with each a different consequent; which 
 consequents, (instead of wholly denying them, as m the last case,) 
 you disjunctively deny; and thence, in the Conclusion, deny disjunc- 
 tively the antecedents: e.g. if A is B, C is D; and if X is Y, E is F: 
 but either C is not D, or E is not F: therefore, either A is not B, or 
 X is not Y. "If this man were wise, he would not speak irreverently 
 of Scripture in jest ; and if he were good he would not do so in earnest ; 
 but he does it, either in jest or in earnest ; therefore he is either not 
 wise or not good." Every Dilemma maybe reduced into two or more 
 simple Conditional Syllogisms: e.g. "if ^schines joined, &c. he is 
 inconsistent; he did '^om, &c. therefore he is inconsistent : and again, 
 if ^schines did not join, <fec. he is unpatriotic; he did not, (fee. 
 therefore he is unpatriotic." Now an opponent might deny either of 
 the minor Premises in the above Syllogisms, but he could not deny 
 both; and therefore he must admit one or the other of the Conclusions : 
 
Chap. IV.] OF MODAL SYLLOGISMS. 51 
 
 for, when a Dilemma is employed, it is supposed that some one of the 
 antecedents mnst be true, (or, in the destructive kind, some one of the 
 consequents false,) but that we cannot tell ivhich of them is so; and 
 this is the reason whv the aro'ument is stated in the form of a Dilemma. 
 From what has been said, it may easily be seen that all Dilemmas are 
 in fact conditional Sf/Uogisms; and that disjunctive Syllogisms may also 
 be reduced to the same form : but as it has been remarked, that all 
 Reasoning Avhatever may ultimately be brought to the one test of 
 Aristotle's "dictum," it remains to show how a Conditional Syllo- 
 gism may be thrown into such a form that that test will at once apply 
 to it ; and this is called the 
 
 Reduction of IIypotheticals. 
 
 § 6. For this purpose we must consider every Conditional Proposi- 
 tion as a universal affirmative categorical Proposition, of which the 
 Terms are entire Propositions, viz. the antecedent answering to the 
 Subject, and the consequent to the Predicate; e.g. to say, "if Louis 
 is a good king, France is likely to prosper;" is equivalent to saying, 
 *■' the case of Louis being a good king, is a case of France being likely 
 to prosper:" and if it be granted, as a minor Premiss to the Con- 
 ditional Syllogism, that " Louis is a good king;" that is equivalent to 
 saying, "the present case is the case of Louis being a good king:" 
 from which you will draw a conclusion in Barbara, {viz. " the present 
 ease is a case of France being likely to prosper,") exactly equivalent 
 to the original Conclusion of the Conditional Syllogism; inz. "France 
 is likely to prosper." As the constructive condition may thus be 
 reduced to Barbara, so may the destructive in like manner, to Cclarent, 
 e.g. "if the Stoics are right, pain is no evil: but pain is an evil; 
 therefore the Stoics are not right;" is equivalent to, " the case of the 
 Stoics being right, is the case of pain being no evil ; the present case 
 is not the case of pain being no evil ; therefore the present case is not 
 the case of the Stoics being right." This is Camestres, which of 
 course is easily reduced to Cclarent. Or, if you will, all Conditional 
 Syllogisms may be reduced to Barbara, by considering them all as 
 constructive ; which may be done, as mentioned above, by converting 
 by negation the major Premiss. (See p. 47, § 3. Ch. IV.) The 
 reduction of Hypotheticals may always be effected in the manner above 
 stated ; but as it produces a circuitous awkwardness of expression, 
 a more convenient form may in some cases be substituted: e.g. in the 
 example above, it may be convenient to take, ''true,'' for one of the 
 Terms: "that pain is no evil is not true; that pain is no evil is 
 asserted by the Stoics ; therefore something asserted by the Stoics is 
 not true." Sometimes again It maybe better to unfold the ai-gurnent 
 into two Syllogisms: e.g. in a former example; first, "Louis is a 
 good king ; the governor of France is Louis ; therefore the governor 
 of France is a good king." And then, second, "every country 
 
52 OF MODAL SYLLOGISMS. [Chap. IV. 
 
 governed by a good king is likely to prosper," &c. [A Dilemma is 
 generally to be reduced into two or more categorical Syllogisms.] 
 And when the antecedent and consequent have each the same Subject, 
 you may sometimes reduce the Conditional by merely substituting a 
 categorical major Premiss for the conditional one: e.g. instead of "if 
 Csesar was a tyrant, he deserved death; he was a tyrant, therefore 
 he deserved death;" you may put for a major, "all tyrants deserve 
 death," &c. But it is of no great consequence, whether Hypotheti- 
 cals are reduced in the most neat and concise manner or not ; since it 
 is not intended that they should be reduced to categorical, in ordinary 
 lyractice, as the readiest ivay of trying their validity, (their own rules 
 being quite sufficient for that purpose ;) but only that we should he 
 able, if required, to subject any argument whatever to the test of 
 Aristotle's dictum, in order to show that all Reasoning turns upon 
 one simple principle. 
 
 Of Enthymeme, Sorites, &c. 
 
 § 7. There are various abridged forms of Argument which may be 
 easily expanded into regular Syllogisms : such as, first, the Enthy- 
 meme, which is a Syllogism with one Premiss suppressed. As all the 
 Terms will be found in the remaining Premiss and Conclusion, it will 
 be easy to fill up the Syllogism by supplying the Premiss that is 
 wanting, whether major or minor: e.g. " Caesar w^as a tyrant; there- 
 fore he deserved death." "A free nation must be happy; therefore 
 the English are happy." 
 
 This is the ordinary form of speaking and writing. It is evident 
 that Enthymemes may be filled up hypothetically. 
 
 2d. When you have a string of Syllogisms, in which the Conclusion 
 of each is made the Premiss of the next, till you arrive at the main 
 and ultimate Conclusion of all, you may sometimes state these briefly, 
 in a form called Sorites; in which the Predicate of the first proposi- 
 tion is made the Subject of the next; and so on, to any length, till 
 finally the Predicate of the last of the Premises is predicated (in the 
 Conclusion) of the Subject of the first: e.g. A is B, B is C, C is D, 
 D is E; therefore A is E. "The English are a brave people ; a 
 brave people are free; a free people are happy; therefore the English 
 are happy." A Sorites then has as many middle Terms as there are 
 intermediate Propositions between the first and the last ; and con- 
 sequently it may be drawn out into as many separate Syllogisms ; of 
 which the first will have, for its major Premiss, the second ; and for 
 its minor y i\\Q first of the Propositions of the Sorites ; as may be seen 
 by the example. It is also evident, that in a Sorites you cannot have 
 more than one negative Proposition, and one particular ; for else, one 
 of the Syllogisms would have its Premises both negative or both 
 particular, (vid. p. 39.) A string of Conditional Syllogisms may in 
 like manner be abridged into a Sorites; e.g. if A is B, C is D; if 
 
Chap. IV.] OF MODAL SYLLOGISMS. 53 
 
 C is D, E Is F; if E is F, G is H; but A is B, therefore G is H. 
 *' If the Scriptures are the word of God, it is important that 
 they should be well explained ; if it is important, Sze. they deserve 
 to be diligently studied ; if they deserve, &l,c. an order of men should 
 be set aside for that purpose: but the Scriptures are the word, ke.; 
 therefore an order of men should be set aside for the purpose, 
 &€." Hence, it is evident, how injudicious an arrangement has 
 been adopted by former writers on Logic, who have treated of the 
 Sorites and Enthymeme before they entered on the subject of 
 Hypotheticals. 
 
 Those who have spoken of induction or of example, as a distinct kind 
 of Argument in a Logical point of view, have fallen into the common 
 error of confounding Logical with PJietoncal distinctions, and have 
 wandered from their subject as much as a writer on the orders of 
 Architecture would do, who should introduce the distinction between 
 buildino-s of stone and of marble. Loii'ic takes no cognizance of 
 induction, for instance, or of a jmo?'i reasoning, »fc;c. as distinct Forms 
 of argument; for when thrown into the syllogistic form, and when 
 letters of the alphabet are substituted for the Terms (and it is thus 
 that Argument is properly to be brought under the cognizance of 
 Logic,) there is no distinction between them ; e.g. a Property which 
 belongs to the ox, sheep, deer, goat, and antelope, belongs to all 
 horned animals ; rumination belongs to these ; therefore, to all. This, 
 which is an inductive argument, is evidently a Syllogism in Barbara. 
 The essence of an inductive argument (and so of the other kinds 
 which are distinguished for it,) consists, not in ilia form of the Argu- 
 ment, but in the relation which the Subject matter of the Premises 
 bears to that of the Conclusion. 
 
 3d. There are various other abbreviations commonly used, which 
 are so obvious as hardly to call for explanation : as, Avhere one of the 
 Premises of a Syllogism is itself the Conclusion of an EnthjTneme 
 which is expressed at the same time: e.g. "all useful studies deserve 
 encouragement ; Logic is such, [since it helps us to reason accuratdy,) 
 therefore it deserves encouragement;" here, the minor Premiss is 
 what is called an Enthymemcdic sentence. The antecedent in that 
 minor Premiss, [i.e. that which makes it Enthymematic,) is called by 
 Aristotle the Frosyllogism. 
 
 It is evident that you may for brevity substitute for any term an 
 equivalent; as in the last examj)lc, " ?^ " for "Logic;" " s?a7i " for 
 " a useful study," <fec. 
 
 4th. And many Syllogisms, which at first appear faulty, Avill often 
 be found, on examination, to contain correct reasoning, and, con- 
 sequently, to be reducible to a regular form ; e.g. when you have, 
 ajyparently, negative Premises, it may liappcn, that by considering one 
 of them as affirmative, (see Ch. II. § 4. p. 35,) the Sylloglsni will 
 be regular: e.g. "no man is ha2)py who is not secure; no tyrant is 
 
54 OF MODAL SYLLOGISMS. [Chap. IV. 
 
 secure; therefore no tyrant is happy," is a Syllogism in Celar&nt.'^ 
 Sometimes there will appear to be too many terms ; and yet there 
 will be no fault in the Reasoning, only an irregularity in the expres- 
 sion: e.g. " no irrational agent could produce a work which manifests 
 design ; the universe is a work which manifests design ; therefore no 
 irrational agent could have produced the universe." Strictly speak- 
 ing, this Syllogism has five Terms ; but if you look to the meaning, 
 you Avill see, that in the first Premiss (considering it as a iKirt of this 
 Argument,) it is not, properly, "an irrational agent " that you are 
 speaking of, and of which you predicate that it could not produce a 
 Avork manifesting design; but rather it is this "work," kc. of which 
 you are speaking, and of which it is predicated that it could not be 
 produced by an irrational agent ; if then you state the Propositions in 
 that form, the Syllogism will be perfectly regular. 
 
 Thus, such a Syllogism as this, "every true patriot is disinterested ; 
 few men are disinterested; therefore few men are true patriots;" 
 might appear at first sight to be in the second Figure, and faulty ; 
 Avhereas it is Barbara, with the Premises transposed; for you do not 
 really predicate of " few men," that they are " disinterested," but of 
 '' disinterested persons,'' that they are "few." Again, "none but 
 candid men are good reasoners ; few infidels are candid ; few infidels 
 are good reasoners." In this it will be most convenient to consider 
 the major Premiss as being "all good reasoners are candid," (which 
 of course is precisely sequipollent to its illative converse by negation ;) 
 and the minor Premiss and Conclusion may in like manner be fairly 
 expressed thus — "most infidels are not candid ; therefore most infidels 
 are not good reasoners:" which is a regular Syllogism in Camestres. 
 Or, if you would state it in the first Figure, thus — those who are not 
 candid (or uncandid) are not good reasoners ; most infidels are not 
 candid ; most infidels are not good reasoners. 
 
 § 8. The foregoing rules enable us to develop the principles on 
 which all Reasoning is conducted, whatever be the Subject matter of 
 it, and to ascertain the validity or fallaciousness of any apparent 
 argument, as far as the form of expression is concerned ; that being 
 alone the proper province of Logic. 
 
 But it is evident that we may nevertheless remain liable to be 
 deceived or perplexed in Argument by the assumption of false or 
 doubtful Premises, or by the employment of indistinct or ambiguous 
 terms ; and, accordingly, many Logical writers, wishing to make 
 their systems appear as perfect as possible, have undertaken to give 
 
 4 If this experiment be tried on a are not enslaved; therefore tliey are 
 
 Syllogism which has 7Y'«^/// negative Pre- happy:" if "enslaved" be regarded as 
 
 mises, the only eft'ect will be to change one of the Terms, and " not enslaved" as 
 
 that fault into another: viz. an excess of another, there will manifestly be four. 
 
 Terms, or, (which is sul)stantially the Hence you may see how very little dif- 
 
 same) an undistributed middle; e.,'/. "an fereuce there is in reality between the 
 
 enslaved people is not happy ; the English different faults which are enumerated. 
 
Chap. IV.] OF MODAL SYLLOGISMS. 55 
 
 rules "for attaining clear ideas," and for "guiding* the judgment;" 
 and fancying or professing themselves successful in this, have 
 consistently enough denominated Logic, the "Art of usinr-- the 
 Reason;" which In truth it Avould he, and would supersede all other 
 studies, if it could alone ascertain the meaning of every Term, and 
 the truth or falsity of every proposition, in the same manner as it 
 actually can the validity of every Argument. And they have heen 
 led into this, partly by the consideration that Logic is concerned 
 about the three operations of the mind — simple Apprehension, 
 Judgment, and Reasoning ; not observing that it is not equally 
 concerned about all ; the last operation being alone its appropriate 
 province ; and the rest being treated of only in reference to that. 
 
 The contempt justly due to such pretensions has most unjustly 
 fallen on the Science Itself, much in the same manner as Chemistry 
 was brought into disrepute among the unthinking by the extravagant 
 pretensions of the Alchemists. And those Logical writers have been 
 censured, not (as they shoidd have been) for mahing such professions, 
 but for imt fill filling them. It has been objected, especially, that the 
 rules of Logic leave us still at a loss as to the most important and 
 difhcult point in Reasoning ; m%. the ascertaining the sense of the 
 terms employed, and removing their ambiguity. A complaint 
 resembling that made (according to a story told by Warburton in his 
 Div. Leg.) by a man who found fault with all the reading-glasses 
 presented to him by the shopkeeper ; the fact being that lie had never 
 learned to read. In the present case, the complaint is the more 
 unreasonable, inasmuch as there neither is, nor ever can jjossibli/ be, 
 any such system devised as will effect the proposed object of clearing 
 up the ambiguity of Terms. It is, however, no small advantage, 
 that the rules of Logic, though they cannot alone, ascertain and clear 
 up ambiguity in any term, point out In wldcli Term of an Argmnent 
 it is to be sought for, directing our attention to the middle Term, ar^ 
 the one on the ambiguity of which a fallacy is likely to be built. 
 
 It will be useful, however, to class and describe the ditfercnt kinds 
 of ambiguity which are to be met Avith ; and also the various ways in 
 which the insertion of false, or, at least, unduly assumed Premises, 
 is most likely to elude observation. And though the i-cmarks which 
 will be offered on these points may not be considered as strictly 
 forming a j^a?'^ of Logic, they cannot be thought out of place, when 
 it is considered how essentially they arc connected with the applica- 
 tion of it. 
 
CHAPTER V. 
 
 OF FALLACIES. 
 
 INTRODUCTION, 
 
 By a Fallacy is commonly miderstood, " any imsomid mode of 
 arguing, which appears to demand our conviction, and to he decisive 
 of tlie question in hand, when in fairness it is not so." As Ave con- 
 sider the ready detection and clear exposure of Fallacies to he hoth 
 more extensively important, and also more difficult than many are 
 aware of, Ave propose to take a Logical view of the suhject ; referring 
 the different Fallacies to the most convenient heads, and giving a 
 scientific analysis of the procedure which takes place in each. 
 
 After all, indeed, in the practical detection of each individual 
 Fallacy, much must depend on natural and acquired acuteness ; nor 
 can any rules be given, the mere learning of Avhich will enable us to 
 apply them with mechanical certainty and readiness: but still we 
 shall find that to take correct general vieAvs of the subject, and to be 
 familiarized with scientific discussions of it, will tend, above all things, 
 to engender such a habit of mind as Avill best fit us for practice. 
 
 Indeed the case is the same Avith respect to Logic in general; 
 scarce any one Avould in ordinary practice, state to himself either his 
 OAvn or another's reasoning in Syllogisms in Barbara at full length ; 
 yet a familiarity Avith Logical principles, tends very much, (as all feel, 
 Avho are really Avell acquainted Avith them,) to beget a habit of clear 
 and sound Reasoning. The truth is, that in this, as in many other 
 things, there are processes going on in the mind (when Ave are practis- 
 ing any thing quite familiar to us) Avith such rapidity as to leave no 
 trace in the memory ; and Ave often apply principles Avhich did not, 
 as far as Ave are conscious, even occur to us at the time. 
 
 It Avould be foreign, hoAvever, to the present purpose, to investi- 
 gate fully the manner in Avhich certain studies operate in remotely 
 jDroducing certain efi'ects on the mind : it is sufficient to establish the 
 fact, that habits of scientific analysis (besides the intrinsic beauty and 
 dignity of such studies) lead to practical advantage. It is on Logical 
 principles therefore that Ave propose to discuss the subject of Fallacies : 
 and it might, indeed, seem to be unnecessary to make any apology 
 for so doing, after AA'hat has been formerly said, generally, in defence 
 of Logic, if the majority of Logical Avriters had not usually followed 
 a very opposite plan. Whenever they have to treat of any thing 
 that is beyond the mere elements of Logic, they totally lay aside all 
 
Chap, v.] of FALLACIES. 57 
 
 reference to the principles which they have heen occupied in estahhsh- 
 ing and explaining, and have recourse to a loose, vague, and popular 
 kind of language ; such as would he the best suited indeed to an 
 exoterical discourse, but seems strangely incongruous in a professed 
 Logical treatise. What should we think of a Geometrical writer, Avho, 
 after having gone through the Elements with strict definitions and 
 demonstrations, should, on proceeding to Mechanics, totally lay aside 
 all reference to scientific principles, — all use of technical terms, — and 
 treat of the subject in undefined terms, and Avith probable and popular 
 arguments ? It would be thought strange, if even a Botanist, when 
 addressing those whom he had been instructing in the principles and 
 the terras of his system, should totally lay these aside when he came 
 to describe plants, and should adopt the language of the vulgar. 
 Surely it aftords but too much plausibility to the cavils of those who 
 scofi:' at Logic altogether, that the very writers who profess to teach 
 it, should never themselves make any application of, or reference to 
 its principles, on those very occasions, when, and wlicn onb/, such 
 application and reference are to be expected. If the principles of 
 any system are well laid down, — if its technical language is well 
 framed, — then, surely those principles and that language will afford, 
 (for those who have once thoroughly learned them,) the best, the 
 most clear, simple, and concise method of treating any subject con- 
 nected with that system. Yet even the accurate Aldricli, in treating 
 of the Dilemma and of the Fallacies, has very much forgotten the 
 Logician, and assumed a loose and rhetorical style of writing, Avithout 
 making any application of the principles he had formerly laid down, 
 but on the contrary, sometimes departing widely from them. 
 
 The most experienced teachers, when addressing those who are 
 familiar with the elementary principles of Logic, think it requisite, 
 not indeed to lead them, on each occasion, throiigli tlie wliole detail of 
 those principles, when the process is quite obvious, but always to j^ii^t 
 them on the road, as it were, to those principles, that they may plainly 
 see their own wa}'' to the end, and take a scientific view of the subject: 
 in the same manner as Mathematical writers, avoid indeed tlie occa- 
 sional tediousness of going all through a very simple demonstration 
 which the learner, if he will, may easily supply ; but yet always speak 
 in strict Mathematical language, and with reference to jMathematical 
 principles, though they do not always state them at full length. We 
 would not profess, therefore, any more than they do, to write (on 
 subjects connected with the science,) in a language intelligible to 
 those who are ignorant of its first rudiments ; to do so, indeed, would 
 imply that we were not taking a scientific view of the subject, nor 
 availing ourselves of the principles wliich had been established, and 
 the accurate and concise technical language Mhich had been framed. 
 
 § 1. The division of Fallacies into those in the words, IN DIC- 
 TIONE, and those in the matter EXTRA DICTIONEM, has not 
 
58 OF FALLACIES. [Chap. V. 
 
 been, by any writers hitherto, grounded on any distinct principle ; at 
 least, not on any that they have themselves adhered to. The con- 
 founding together, however, of these two classes is highly detrimental 
 to all clear notions concerning Logic ; being obviously allied to the 
 prevailing erroneous views which make Logic the art of employing 
 the intellectual faculties in general, having the discovery of truth for 
 its object, and all kinds of knowledge for its proj)er subject matter ; 
 with all that train of vague and groundless speculations which have 
 led to such interminable confusion and mistakes, and afforded a 
 pretext for such clamorous censures. 
 
 It is important, therefore, that rules should be given for a division 
 of Fallacies into Logical, and Non-logical, on such a principle as shall 
 keep clear of all this indistinctness and perplexity. 
 
 If any one should object that the division we adopt is in some 
 degree arbitrary, placing under the one head Fallacies, which many 
 might be disposed to place under the other, let him consider not only 
 the indistinctness of all former divisions, but the utter impossibility 
 of framing any that shall be completely secure from the objection 
 urged, in a case where men have formed such various and vague 
 notions, from the very want of some clear principle of division. Nay, 
 from the elliptical form in which all Reasoning is usually expressed, 
 and the peculiarly involved and oblique form in which Fallacy is for 
 the most part conveyed, it must of course be often a matter of .doubt, 
 or rather, of arbitrary choice, not only to which genus each kind of 
 Fallacy should be referred, but even to which kind to refer any one 
 individual Fallacy : for since in any course of argument, one Premiss 
 is usually suppressed, it frequently happens, in the case of a Fallacy, 
 that the hearers are left to the alternative of supplying either a 
 Premiss which is not true, or else, one which does not jjrove the con- 
 clusion ; e.g. if a man expatiates on the distress of the country, and 
 thence argues that the government is tyrannical, we must suppose 
 him to assume eitJier that " every distressed country is under a 
 tyranny," which is a manifest falsehood, or, merely that "every 
 country under a tyranny is distressed," which, however true, proves 
 nothing, the middle term being undistributed. Now, in the former 
 case, the Fallacy would be referred to the head of " extra dictionem;'' 
 in the latter, to that of ''m dlctione:'' Avhich are we to suppose the 
 speaker meant us to understand ? surely just whichever each of 
 his hearers might happen to prefer : some might assent to the false 
 Premiss ; others, allow the unsound Syllogism : to the Sophist himself 
 it is indifferent, as long as they can but be brought to admit the 
 conclusion. 
 
 Without pretending then to conform to every one's mode of speak- 
 ing on the subject, or to lay down rules which shall be, in themselves, 
 (without any call for labour or skill in the person who employs them,) 
 readily applicable to, and decisive on each individual case ; we propose 
 
Chap. V.] OF FALLACIES. 59 
 
 a division which is at least perfectly clear in its main principle, and 
 coincides, perliaps, as nearly as possible with the established notions 
 of Logicians on the subject. 
 
 § 2. In every Fallacy, the conclusion either does, or does not 
 folloiD from the Premises: where the conclusion does not follow from 
 the Premises, it is manifest that the fault is in the Ilcasoning, and in 
 that alone ; these, therefore, we call Logical Fallacies,'^ as being 
 properly violations of those rides of Reasoning Avhich it is the province 
 of Logic to lay do^^^l. Of these, however, one kind are more lourely 
 Logical, as exhibiting their fallaciousness by the bare form of the 
 expression, without any regard to the meaning of the terms : to which 
 class belong: 1st. undistributed middle; 2d. ilhcit process; 3d. 
 negative Premises, or affirmative conclusion from a negative Premiss, 
 and vice versa: to which may be added, 4th. those which have 
 palpably [i.e. expressed) more than three terms. The other kind 
 may be most properly called semi-logical ; viz. all the cases of 
 ambiguous middle term except its non-distribution : for though in such 
 cases the Conclusion does not follow, and though the rules of Logic 
 show that it does not, as soon as the ambiguity/ of the middle term is 
 ascertained, yet the discovery and ascertainment of this ambiguity 
 requires attention to the sense of the term, and knowledge of the 
 subject matter; so that here, Logic "teaches us not hoio to find the 
 Fallacy, but only icliere to search for it," and on what principles to 
 condemn it. Accordingly it has been made a subject of bitter com- 
 plaint against Logic, that it presupposes the most difficult point to 
 be already accomplished, viz. the sense of the terms to be ascertained. 
 A similar objection might be urged against every other art in 
 existence ; e.g. against Agriculture, that all the precepts for the 
 cultivation of land presuppose the possession of a farm ; or against 
 Perspective, that its rules are useless to a blind man. The objection 
 is indeed peculiarly absurd when urged against Logic, because the 
 object which it is blamed for not accomplishing, cannot j)Ossihhi be 
 within tliC province of cnvi one art whatever. Is it indeed possible or 
 conceivable that there should be any method, science, or system, 
 that should enable one to know the full and exact meaning of every 
 term in existence ? The utmost that can be done is to give some 
 general rules that may assist us in this work ; which is done in the 
 two first parts of Logic. 
 
 The very author of the objection says, "this (the comprehension 
 of the meaning of general terms) is a study which every individual 
 must carry on for himself; and of wliich no rules of Logic (how 
 useful soever thcv may be in directino- our labours) can supersede the 
 necessity." D. Stewart, Phil. Vol.ll. Ch. 11. S. 2. 
 
 Nothing perhaps tends more to conceal from men their iujperfect 
 
 5 Just as we call that a criminal Court in which crimes are judged 
 
60 OF FALLACIES. [Chap. V. 
 
 conception of tlie meaning of a term, than the circumstance of their 
 being able fully to comprehend a j^^^ocess of Reasoning in which it is 
 involved, without attaching any distinct meaning, or perhaps any 
 meaning at all to that term ; as is evident when ABC, are used to 
 stand for terms, in a regular Syllogism : thus a man may be famil- 
 iarized with a term, and never find himself at a loss from not com- 
 prehending it ; from which he will be very likely to infer that he does 
 comprehend it, when perhaps he does not, but employs it vaguely and 
 incorrectly, which leads to fallacious reasoning and confusion. It 
 must be owned, hoAvever, that many Logical writers have, in great 
 measure, brought on themselves the reproach in question, by calling 
 Logic " the right use of Reason," laying down "rules for gaining 
 clear ideas," and such-like d'ha^cvsiu, as Aristotle calls it. JRhet. 
 Book I. Ch. IL 
 
 § 3. The remaining class {viz. where the Conclusion does follow 
 from the Premises) may be called the Material, or Non-logical 
 Fallacies: of these there are two kinds; 1st. Avhen the Premises are 
 such as ought not to have been assumed ; 2d. wlien the Conclusion 
 is not the one required, but irrelevant ; which Fallacy is called 
 " ignoratio elenchi/' because your argument is not the elenchus, {i.e. 
 proof of the contradictory) of your opponent's assertion, which it 
 should be ; but proves, instead of that, some other proposition 
 resembling it. Hence, since Logic defines what Conti*adiction is, 
 some may choose rather to range this with the Logical Fallacies, as 
 it seems, so far, to come under the jurisdiction of that art : neverthe- 
 less, it is perhaps better to adhere to the original division, both on 
 account of its clearness, and also because few A^ould be inclined to 
 apply to the Fallacy in question the accusation of being inconclusive, 
 and consequently illogical reasoning": besides which, it seems an 
 artificial and circuitous way of speaking, to suppose in all cases an 
 opjyonent and a contradiction; the simple statement of the matter 
 being this, — I am required, by the circumstances of the case, (no 
 matter Avhy) to prove a certain Conclusion ; I prove, not that, but 
 one which is likely to be mistaken for it ; — in this lies the Fallacy. 
 
 It might be desirable, therefore, to lay aside the name of " igno- 
 ratio elenchi,'' but that is so generally adopted as absolutely to require 
 some mention to be made of it. The other kind of Fallacies in the 
 matter Avill comprehend, (as far as the vague and obscure language of 
 Logical writers will allow us to conjecture,) the Fallacy of " non 
 causa 2^i^o causa,'' and that of " jjetitio principii:'' of these, the for- 
 mer is by them distinguished into " a non vera p)ro vera,''' and "a non 
 tali pro tali;" this last Avould appear to be arguing from a case not 
 jmrallel as if it ivere so ; Avhich, in Logical language, is, having the 
 suppressed Premiss false ; (for it is in that the p)arallelism is affirmed) 
 and the "a non vera p)ro vera" Avill in like manner signify the 
 expressed Premiss being false; so that this Fallacy will turn out to be, 
 
Chap. V.] OF FALLACIES. 61 
 
 in plain terms, neither more nor less than falsity, (or unfair assump- 
 tion) of a Premiss. 
 
 The remaining kind, "^jeizYw j^rincipii,'' (begging the question,) 
 takes place when a Premiss, whether true or false, is either plainly 
 equivalent to the Conclusion, or depends on it for its own reception. 
 It is to be observed, however, that in all correct Reasoning the Pre- 
 mises must, virtually, imply the conclusion ; so that it is not possible 
 to mark precisely the distinction between the Fallacy in question and 
 fair argument ; since that may be correct and fair Reasoning to one 
 person, which would be, to another, begging the question, since to 
 one the Conclusion might be more evident than the Premiss, and to 
 the other, the reverse. The most plausible form of this Fallacy is 
 arguing in a circle ; and the greater the circle, the harder to detect. 
 
 § 4. There is no Fallacy that may not properly be included under 
 some of the foregoing heads ; those which in the Logical Treatises are 
 separately enumerated, and contradistinguished from these, beinj^ in 
 reality instances of them, and therefore more properly enumerated in 
 the subdivision thereof; as in the scheme annexed. 
 
02 
 
 OF FALLACIES. 
 
 [Chap. V. 
 
 
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Chap. V.] OF FALLACIES. 63 
 
 § 5. On each of the Fallacies which have heen thus enumerated 
 and distinguished, Ave propose to offer some more particular remarks : 
 but before we proceed to this, it will be proper to premise two general 
 observations, 1st. on the importance, and 2d. the difficulty, of detect- 
 ing and describing Fallacies ; both have been already slightly alluded 
 to, but it is requisite that they should here be somewhat more fully 
 and distinctly set forth. 
 
 1st. It seems by most persons to be taken for granted that a Fallacy 
 is to be dreaded merely as a weapon fashioned and wielded by a skil- 
 ful Sophist : or if they allow that a man may with honest intentions 
 sHde into one, unconsciously, in the heat of argument, still they seem 
 to suppose that where there is no disjMe, there is no cause to dread 
 Fallacy; whereas there is much danger, even in what may be called 
 solitary Reasoning, of sliding unawares into some Fallacy, by which 
 one may be so far deceived as even to act upon the Conclusion thus 
 obtained. By solitary Reasoning is meant the case in which we are 
 not seeking for arguments to prove a given question, but labouring to 
 elicit from our previous stock of knoAvledge some useful inference. To 
 select one from innumerable examples which might be cited, and of 
 which some more will occur in the subsequent part of this Essay; it 
 is not improbable that many indifferent sermons have been produced 
 by the ambiguity of the word "j^/am:" a young divine perceives the 
 truth of the maxim, that "for the lower orders one's lano-uao-e cannot 
 be too 2^l(iin; {i.e. clear and j'^ersjncuous, so as to require no learning 
 nor ingenuity to understand it,) and when he proceeds to practice, the 
 word " jiam" indistinctly flits before him, as it were, and often checks 
 him m the use of ornaments of style, such as metaphor, epithet, anti- 
 thesis, &,o. which are opposed to "plainness" in a totally different 
 sense of the word, being by no means necessarily adverse to p^^rsin- 
 cuity, but rather, in many cases, conducive to it ; as may be seen in 
 several of the clearest of our Lord's discourses, which are of all others 
 the most richly adorned with figurative language. So far, indeed, is 
 an ornamented style from being unfit for the vulgar, that they are 
 pleased with it even in excess. Yet the desire to be "plain," com- 
 bined with that dim and confused notion which the ambiguity of the 
 word produces in such as do not separate in their minds, and set 
 distinctly before themselves, the two meanings, often causes them to 
 write in a dry and bald style, which has no advantage in point of per- 
 spicuity, and is least of all suited to the taste of the vulgar. Tlie 
 above instance is not drawn from mere conjecture, but from actual 
 experience of the fact. 
 
 Another instance of the strong influence of words on our ideas may 
 be adduced from a witlely different subject: most persons feel a cer- 
 tain degree of smprise on first hearing of the result of some late 
 experiments of the agricultural Chemists, by which they have ascer- 
 tained that universally what are called heavy soils are specifically the 
 
64 OF FALLACIES. [Chap. V. 
 
 lightest ; and vice versa. Whence this surprise ? for no one ever 
 distinctly believed the estabhshed names to be used in the Hteral and 
 jmmary sense, in consequence of the respective soils having been 
 weighed together ; indeed it is obvious on a moment's reflection, that 
 tenacious clay soils (as well as muddy roads) are figuratively called 
 heavy from the difficulty of ploughing or passing over them, which 
 produces an effect like that of bearing or dragging a heavy weight ; 
 yet still the terms, "light " and "heavy," though used figuratively, 
 have most undoubtedly introduced into men's minds something of the 
 ideas expressed by them in their primitive sense. So true is the 
 ingenious observation of Hobbes, that "words are the counters of 
 wise men, and the money of fools." 
 
 More especially deserving of attention is the influence of analogical 
 terms in leading men into erroneous notions in Theology; Avhere the 
 most important terms are analogical ; and yet, they are contmually 
 employed in Reasoning without due attention (oftener through want 
 of caution than by unfair design) to their analogical nature ; and most 
 of the errors into which Theologians have fallen may be traced, in part, 
 to this cause. 
 
 Thus much, as to the extensive practical influence of Fallacies, and 
 the consequent high importance of detecting and exposing them. 
 
 § 6. 2dly. The second remark is, that while sound Reasoning is 
 ever the more readily admitted, the more clearly it is perceived to be 
 such. Fallacy, on the contrary, being rejected as soon as perceived, 
 will, of course, be the more likely to obtain reception, the more it is 
 obscured and disguised by obliquity and complexity of expression : it 
 is thus that it is the most likely either to slip accidentally from the 
 careless reasoner, or to be brought forward deliberately by the Sophist. 
 Not that he ever wishes that obscurity and complexity to be perceived; 
 on the contrary it is for his purpose that the expression should appear 
 as clear and simple as possible, while in reahty it is the most tangled 
 net he can contrive. Thus, whereas it is usual to express our 
 Reasoning elliptically, so that a Premiss, (or even two or three entire 
 steps in a course of argument) which may be readily supplied, as 
 being perfectly obvious, shall be left to be understood, the Sophist in 
 like manner suppresses what is not obvious, but is in reality the 
 weakest part of the argument ; and uses every other contrivance to 
 withdraw om- attention (his art closely resembling the juggler's) from 
 the quarter where the Fallacy hes. Hence the uncertainty before 
 mentioned, to which class any individual Fallacy is to be referred : 
 and hence it is tliat the difficulty of detecting and exposing Fallacy, 
 is so much greater than that of comprehending and developing a process 
 of sound argument. It is like the detection and aj^prehension of a 
 criminal in spite of all his arts of concealment and disguise ; when 
 this is accomplished, and he is brought to trial with all the evidence of 
 his guilt produced, his conviction and punishment are easy; and this 
 
Chap. V.] OF FALLACIES. Q5 
 
 is precisely the case with those Fallacies which are given as examples 
 in Logical Treatises ; they are in fact already detected, by being 
 stated in a plain and regular form, and are, as it were, only brought 
 up to receive sentence. Or again, fallacious Reasoning may be com- 
 pared to a perplexed and entangled mass of accouiUs, which it requires 
 much sagacity and close attention to clear up, and display in a regular 
 and intelligible form; though lolien this is once accomjMsIied, the 
 Avhole appears so perfectly simjjle, that the unthinking are apt to 
 undervalue the skill and pains which have been employed upon it. 
 
 Moreover, it shoidd be remembered that a very long discussion is 
 one of the most effectual veils of Fallac3\ Sophistry, like poison, is 
 at once detected, and nauseated when presented to us in a concen- 
 trated form ; but a Fallacy which when stated barely, in a few 
 sentences, would not deceive a child, may deceive half the world if 
 diluted in a quarto volume. To speak, therefore, of all the Fallacies 
 that have ever been enumerated as too glaring and obvious to need 
 even being mentioned, because the simple instances given in books, 
 and there stated in the plainest and consequently most easily detected 
 form, are such as would (in that form) deceive no one ; this, surely, 
 shows either extreme weakness, or else unfairness. It may readily 
 be allowed, indeed, that to detect individual Fallacies, and bring them 
 under the general rules, is a harder task than to Icq/ doion those 
 general rides ; but this does not prove that the latter office is trifling 
 or useless, or that it does not essentially conduce to the performance 
 of the other : there may be more ingenuity shoAvn in detecting and 
 arresting a malefactor, and convicting him of the fact, than in laying- 
 down a law for the trial and punishment of such a person ; but the 
 latter office, i.e. that of a legislator, is surely neither unnecessary nor 
 trifling. 
 
 It should be added, that a close observation and Logical analysis of 
 fallacious arguments, as it tends (according to what has been already 
 said) to form a habit of mind well suited for the practical detection 
 of Fallacies ; so, for that very reason, it will make us the more 
 careful in makino; cdloioance for them ; i.e. bearinti- in mind how much 
 men in general are liable to be influenced by them : e.g. a refuted 
 argument ougJit to go foi" nothing; but in fad it will generally prove 
 detrimental to the cause, from the Fallacy which will be presently 
 explained. No one is more likely to be practically aware of this, and 
 to take precautions accordingly, than he who is most versed in the 
 Avliole theory of Fallacies; for the best Logician is the least likely to 
 calculate on men in genercd being such. 
 
 Of Fallacies in Form, 
 
 § 7. Enough has already been said in the preceding compendium ; 
 and it has been remarked above, that it is often left to our 'choice to 
 refer an individual Fallacy to this head or to another. 
 
 P 
 
66 OF FALLACIES. [Chap. V. 
 
 To the present class vre may the most conveniently refer those 
 Fallacies, so common in practice, of supposing the Conclusion false, 
 because the Premiss is false, or because the argument is unsound ; and 
 inferring the truth of the Premiss from that of the Conclusion ; e.g. if 
 any one argues for the existence of a God, from its being universally 
 believed, a man might perhaps be able to refute the argument by 
 producing an instance of some nation destitute of such belief ; the 
 argument ougM then (as has been observed above) to go for nothing: 
 but many would go further, and think that this refutation had 
 disproved the existence of a God ; in which they would be guilty of 
 an illicit j^f^cess of the major term; viz. "whatever is universally 
 believed must be true ; the existence of a God is not universally 
 believed; therefore it is not true." Others again from being con- 
 vinced of the truth of the Conclusion would infer that of the Premises ; 
 which would amount to the Fallacy of undistributed middle: viz. 
 " what is universally believed, is true ; the existence of a God is true ; 
 therefore it is universally believed." Or, these Fallacies might be 
 stated in the hypothetical form ; since the one evidently proceeds 
 from the denial of the antecedent to the denial of the consequent ; 
 and the other from the establishing of the consequent to the inferring 
 of the antecedent ; which two Fallacies correspond respectively with 
 those of illicit process of the major, and undistributed^ middle. 
 
 Fallacies of this class are very much kept out of sight, being 
 seldom perceived even by those who employ them; but of their 
 practical importance there can be no doubt, since it is notorious that 
 a weak argument is always, in practice, detrimental; and that there is 
 no absurdity so gross which men will not readily admit, if it appears 
 to lead to a Conclusion of what they are already convinced. Even a 
 candid and sensible writer is not unlikely to be, by this means, misled, 
 when he is seeking for arguments to support a Conclusion Avhich he 
 has long been fuDy convinced of himself; i.e. he will often use such 
 arguments as would never have convinced himself, and are not likely to 
 convince others, but rather (by the operation of the converse Fallacy) 
 to confirm in their dissent those who before disagreed with him. 
 
 It is best therefore to endeavour to put yourself in the place of an 
 opponent to your own arguments, and consider whether you could not 
 find some objection to them. The applause of one^s own. party is a 
 very unsafe ground for judging of the real force of an argumentative 
 work, and consequently of its real utiUty. To satisfy those who were 
 doubting, and to convince those who were opposed, is the only sure 
 test ; but these are seldom very loud in their applause, or very forward 
 in bearing their testimony. 
 
 Of Ambiguous Middle. 
 
 § 8. That ease in which the middle is undistributed, belongs of 
 course to the preceding head, the fault being perfectly manifest from 
 
Chap. V.] OF FALLACIES. Q7 
 
 tlie mere form of the expression: in that case tlie extremes are 
 compared with tivo j^a^ts of the same term ; but in the Fallacy which 
 has been called semi-logical, (which we are now to speak of) the 
 extremes are compared with tioo different terms, the middle being 
 used in two different senses in the two Premises. 
 
 And here it may be remarked, that when the argument is brought 
 into the form of a regular Syllogism, the contrast between these two 
 senses will usually appear very striking, from the two Premises being 
 placed together; and hence the scorn with which many have treated 
 the very mention of the Fallacy of equivocation, deriving their only 
 notion of it from the exposure of it in Logical Treatises ; whereas, in 
 practice it is common for the two Premises to be placed very far 
 apart, and discussed in different parts of the discourse ; by which 
 means the inattentive hearer overlooks any ambiguity that may exist 
 in the middle term. Hence the advantage of Logical habits, to fix 
 our attention strongly and steadily on the imioortant terms of an 
 argument. 
 
 One case which may be regarded as coming mider the head of 
 Ambiguous middle, is, what is called '' Fallacia Figurce Dictionis,'' 
 the Fallacy built on the grammatical structure of language, from 
 men's usually taking for granted that' par onymous words, {i.e. those 
 belonging to each other, as the substantive, adjective, verb, &lc. of 
 the same root) have a precisely correspondent meaning : which is by 
 no means universally the case. Such a Fallacy could not indeed be 
 even exhibited in strict Logical form, which would preclude even the 
 attempt at it, since it has two middle terms in sound as well as sense ; 
 but nothing is more common in practice than to vary continually the 
 terms employed, with a view to grammatical convenience ; nor is 
 there any thing unfair in such a practice, as long as the meaning is 
 preserved unaltered: e.g. "murder should be punished with death; 
 this man is a murderer; therefore he deserves to die;" *fcc. etc. 
 Here we proceed on the assumption (in this case just) that to commit 
 murder and to be a murderer, — to deserve death and to be one who 
 ought to die, are, respectively, equivalent expressions ; and it would 
 frequently prove a heavy inconvenience to be debarred this kind of 
 liberty ; but the abuse of it gives rise to the Fallacy in question : e.g. 
 projectors are mifit to be trusted ; this man has formed a jyrojcct, 
 therefore he is imfit to be trusted : '^ here the Sophist proceeds on the 
 hypothesis that he who forms a, project must be a projector; whereas 
 the bad sense that commonly attaches to the latter word, is not at all 
 implied in the former. 
 
 This Fallacy may often be considered as lying not in the middle, 
 but in one of the terms of the Conclusion ; so that the Conclusion 
 drawn shall not be, in reality, at all warranted by the Premises, 
 
 « Wealth o/NcUions, A. Smith: Usury. 
 
68 OF FALLACIES. [Chap. V. 
 
 tliougli it will appear to be so, by means of the grammatical affinity 
 of the words : e.g. "to be acquainted with the guilty is a presumjJtion 
 of guilt ; this man is so acquainted ; therefore we may presume that 
 he is guilty:" this argument proceeds on the supposition of an exact 
 correspondence between "preswrne " and "presz/mj^^zoii," which 
 however does not really exist; for " presumption " is commonly used 
 to express a kind of slight susjoicion; whereas "to presume" amounts 
 to absolute belief. 
 
 The above remark Avill apply to some other cases of ambiguity of 
 term ; viz. the Conclusion will often contain a term, which (though 
 not as here, different in expression from the corresponding one in the 
 Premiss, yet) is liable to be understood in a sense diiferent from that 
 which it bears to the Premiss ; though of course such a Fallacy is 
 less common, because less hkely to deceive, in those cases, than in 
 this; wliere the term used in the Conclusion, though professing to 
 correspond with one in the Premiss, is not the very same in expres- 
 sion, and therefore is more certain to convey a different sense ; which 
 is what the Sophist wishes. 
 
 There are innummerable instances of a non-correspondence in 
 paronymous words, similar to that above instanced ; as between art 
 and artful, design and designing, faith and faithful, &,c. ; and the 
 more slight the variation of meaning, the more likely is the Fallacy 
 to be successful ; for when the words have become so widely removed 
 in sense as "pity " and "pitiful," every one would perceive such a 
 Fallacj^ nor could it be employed but in jest. 
 
 This Fallacy cannot in practice be refuted, by stating merely the 
 impossibility of reducing such an argument to the strict Logical form ; 
 (unless indeed you are addressing regular Logicians,) you must find 
 some way of pointing out the non-correspondence of the terms in 
 question ; e.g. with respect to the example above, it may be remarked, 
 that we speak of strong or faint "presumption," but yet we use no 
 such expression in conjunction with the verb "presume," because the 
 word itself imp)lies strength. 
 
 No Fallacy is more common in controversy than the present, since in 
 this way the Sophist will often be able to misinterpret the propositions 
 which his opponent admits or maintains, and so employ them against 
 him : thus in the examples just given, it is natural to conceive one of 
 the Sophist's Premises to have been borrowed from his opponent. 
 
 Perhaps a dictionary of such paronymous words as do not regularly 
 correspond in meaning, would be nearly as useful as one of synonymes ; 
 i.e. properly speaking, oi pseudo-synonymes.\Th.e present Fallacy is 
 nearly allied to, or rather perhaps may be regarded as a branch of 
 that founded on Etymology; viz. when a term is used, at one time, in 
 its customary, and at another, in its Etymological sense. Perhaps 
 no example of this can be found that is more extensively and 
 mischievously employed than in the case of the word represe^dative: 
 
Chap. V.] OF FALLACIES. 69 
 
 assuming that its right meaning must correspond exactly with the 
 strict and original sense of the verb represent, the Sophist persuades 
 the multitude, that a member of the House of Commons is bound to 
 be guided in all points by the opinion of his constituents ; and, in 
 short, to be merely their spokesman: whereas law and custom, which 
 in this case may be considered as fixing the meaning of the term, 
 require no such thing, but enjoin the representative to act according 
 to the best of his ovm judgment, and on his own responsibility. H. 
 Tooke has furnished a whole magazine of such weapons for any 
 Sophist who may need them, and has furnished some specimens of 
 the employment of them. 
 
 § 9. It is to be observed, that to the head of Ambiguous middle 
 should be referred what is called jPc/ZZac^'a Plurium Interrogationum,'' 
 which may very properly be named, simply, *'the Fallacy of Interro- 
 gation;" viz. the Fallacy of asking several questions which appear 
 to be but one ; so that whatever one ansAver is given, being of course 
 applicable to one only of the implied questions, may be interpreted as 
 apphed to the other ; the refutation is, of course, to reply separately 
 to each question, i.e. to detect the ambiguity. 
 
 We have said several " questions which ap)pear to he hut one,'"' for 
 else there is no Fallacy ; such an example, therefore, as " estne Jwmo 
 animal et lapis? " which Aldrich gives, is foreign to the matter in 
 hand ; for there is nothing unfair in asking two distinct questions, or 
 assertmg two distinct propositions, distinctly and avcnuedbj. 
 
 This Fallacy may be referred, as has been said, to the head of 
 Ambiguous middle: in all Reasoning it is very common to state one 
 of the Premises in form of a question, and Avhen that is admitted, or 
 supposed to be admitted, then to fill up the rest ; if then one of the 
 terms of that question be ambiguous, whichever sense the opponent 
 replies to, the Sophist assumes the other sense of the tenii in the 
 remaining Premiss. It is therefore very common to state an 
 unequivocal argument, in form of a question so worded, that there 
 shall be little doubt tvhich reply will be given : but if there be such 
 doubt, the Sophist must have tivo Fallacies of equivocation ready : 
 e.g. the question "whether anything vicious is expedient," discussed 
 in Cic. Of., Book III. (where, by the bye, he seems not a little per- 
 plexed with it himself,) is of the character in question, from the 
 ambiguity of the word "expedient,'' which means sometimes, "con- 
 ducive to temporal prosperity," sometimes, "conducive to the greatest 
 good:" whichever answer therefore was given, the Sophist might 
 have a Fallacy of equivocation founded on this term ; viz. if the 
 answer be in the negative, his argument Logically developed, will 
 stand thus, — "what is vicious is not expedient; whatever conduces 
 to wealth and aggrandizement is expedient, therefore it cannot bo 
 vicious: " if, in the affirmative, then thus, "whatever is expedient is 
 desirable; something vicious is expedient, therefore desirable.' 
 
70 OF FALLACIES. [Chap. V. 
 
 This kind of Fallacy is frequently employed in such a manner, that 
 the uncertainty shall be, not about the meaning, but the extent of a 
 term, i.e. Avhether it is distributed or not: e.g. " did A B in this case 
 act from such and such a motive ? ' ' which may imply either, ' ' was it 
 his sole motive?" or " was it one of his motives?" in the former case 
 the term " that which actuated A B" is distributed; in the latter 
 not : now if he acted from a mixture of motives, whichever answer you 
 give, may be misrepresented and thus disproved. 
 
 § 10. In some cases of Ambiguous middle, the term in question may 
 be considered as having m itself, from its own equivocal nature, two 
 significations; (which apparently constitutes the " Fcdlacia equivo- 
 cationis of Logical writers ;) others again have a middle term which is 
 ambiguous from the context, i.e. from what is understood in conjunc- 
 tion with it : this division will be found useful, though it is impossible 
 to draw the line accurately in it. 
 
 There are various ways in which words come to have two meanings ; 
 1st. \r^ accident; [i.e. when there is no perceptible connection between 
 the two meanings ;) as " light "signifies both the contrary to " heavy," 
 and the contrary to "dark." Thus, such proper names as John or 
 Thomas, &c. whicli happen to belong to several different persons, are 
 ambiguous, because they have a different signification in each case 
 where they are applied. Words which fall under this first head are 
 what are the most strictly called equivocal. 
 
 2dly. There are several terms in the use of which it is necessary 
 to notice the distinction between first and second intention : the ' ' first 
 intention" of a term, (according to the usual acceptation of this 
 phrase,) is a certain vague and general signification of it, as opposed 
 to one more precise and limited, which it bears in some particular art, 
 science, or system, and which is called its "second intention." 
 Thus, among farmers in some parts, the word "beast" is applied 
 particularly and especially to the ox kind; and "bird," in the lan- 
 guage of many sportsmen, is in like manner appropriated to the par- 
 tridge : the common and general acceptation (Avhich every one is well 
 acquainted with) of each of those two words, is the first intention of 
 each ; the other, its second intention. 
 
 It is evident that a term may have several second intentions, 
 according to the several systems into which it is introduced, and of 
 which it is one of the technical terms : thus line signifies, in the Art 
 Military, a certain form of drawing up ships or troops ; in Geography, 
 a certain division of the earth ; to the fisherman, a string to catch 
 fish, &c. (kc; all which are so many distinct second intentions, in 
 each of which there is a certain signification of " extension in length" 
 which constitutes the first intention, and which corresponds pretty 
 nearly with the employment of the term in Mathematics. 
 
 It will sometimes happen, that a term shall be employed always in 
 some one or other of its second intentions ; and never, strictly, in the 
 
Chap. V.] OF FALLACIES. 71 
 
 first, though that first Intention Is a part of its signi/lcation In each case. 
 It Is evident, that the utmost care is requisite to avoid confounding 
 together, either the first and second intentions, or the diflferent second 
 intentions with each other. 
 
 3dly. When two or more things are connected by resemihlance or 
 analogy, they will frequently have the same name. Thus a " Uade 
 of grass," and the contrivance in buikling called a ^^ dove-tail," are so 
 called from their resemblance to the blade'' of a sword, and the tail of 
 a real dove : but two things may be connected by aiudogy, though they 
 have in themselves no resemblance: for analogy is the resemblance of 
 ratios, (or relations,) thus, — as a sweet taste gratifies the palate, so 
 does a sioeet sound gi^ati/y the ear; and hence the same word, ''sweet,'' 
 is applied to both, though no flavour can resemble a sound in itself: 
 so, the leg of a table, does not resemble that of an animal ; nor the 
 foot of a mountain that of an animal : but the leg answers tJie same 
 purjyose to the table, as the leg of an animal to that animal ; the foot 
 of a mountain has the same situation relatively to the mountain, as 
 the foot of an animal, to the animal ; this analogy, therefore, may be 
 expressed like a Mathematical analogy; (or proportion) leg : animal : : 
 supporting-stick : table. — In all these cases, (of this 3d head,) one of 
 the meanings of the word Is called by Logicians j)ro2oer, i.e. original 
 or primary ; the other, improper, secondary or transferred : thus, 
 sweet, Is originally and properly applied to tastes; secondarily and 
 improperly, {i.e. by analogy,) to sounds : thus also, dove-tail Is apphed 
 secondarily, though not by analogy, but by direct resemblance, to the 
 contrivance In bulldlno; so called. When the secondarv meanino- of 
 a word is founded on some fanciful analogy, and especially when It is 
 introduced for ornament sake, we call this a metaphor; as when we 
 speak of "a ship's 2?loiighing the deep." The turning up of the 
 surface being essential indeed to the plough, but incidental cuily to 
 the ship ; but If the analogy be a more Important and essential one, 
 and especially If we have no other word to express our meaning but 
 this transferred one, Ave then call It merely an analogous word, (though 
 the metaplior Is analogous also ;) e.g. one would hardly call It meta- 
 phoriccd or figuralive language to speak of the leg of a table, or mouth 
 of a river. 
 
 4thly. Several things may be called by the same name, (though 
 they have no connection of resemblance or analogy,) from being con- 
 nected by vicinity of time or p>lace; under which head will come the 
 connection of cause and effect, or of part and Avhole, <tc. Thus a 
 door signifies both an opening In the wall, (more strictly called the 
 door-way,) and a board which closes It: which are things neither 
 similar nor analogous. When I say, ** the rose smells sweet," and " I 
 
 7 Unless, indeed, the primary applica- wliicli is pcrliaps more probablo; but tlie 
 tion of the term be to the leaf of grass, and question is unimportant in tlie present 
 the secondary, to cutting instruments; case. 
 
72 OF FALLACIES. [Chap. V. 
 
 smell the rose:" the word '* smell " has two meanings : in the latter 
 sentence, I am speaking of a certain sensation in my own mind ; in 
 the former, of a certain quality in the flower, which produces that 
 sensation, but which of course cannot in the least resemble it : and 
 here the word smell, is applied with equal propriety to both. Thus 
 we speak of Homer, for "the works of Homer;" and this is a 
 secondary or transferred meaning: and so it is when we say, *' a good 
 shot," for a good marksman: but the word "shot'^ has two other 
 meanings, which are both equally proper ; viz. the thing imt into a 
 gun in order to be discharged from it, and the act of discharging it. 
 
 Thus, "learning'^ signifies either the act of acquiring knowledge, 
 or the knowledge itself; e.g. " he neglects his learning." " Johnson 
 was a man of learning." Possession is ambiguous in the same man- 
 ner ; and a multitude of others. Much confusion often arises from 
 ambiguity of this kind, when unpercelved ; nor is there any point in 
 which the copiousness and consequent precision of the Greek language 
 is more to be admired than in its distinct terms for expressing an act, 
 and the result of that act; e.g. 'x^oc^ig, "the doing of any thing;" 
 ir^oL^y.a,, "the thing done;" so, ooV/? and §2^oi/, Ti'^i^is and X'^ju,/^oi, &c. 
 It will very often happen, that two of the meanings of a word will 
 have no connection with one another, but will each have some con- 
 nection with a third. Thus "martyr," originally signified a witness, 
 thence it was apphed to those who suffered in bearing testimony to 
 Christianity ; and thence again it is often applied to sufi'erers in 
 general : the first and third significations are not the least connected. 
 Thus ^'post" signifies originally a pillar, {2:)6stum, from j90?io;) then 
 a distance marked out by posts ; and then the carriages, messengers, 
 &c. that travelled over this distance. 
 
 Innumerable other ambiguities might be brought under this fourth 
 head, which indeed comprehends all the cases which do not fall under 
 the three others. 
 
 The remedy for ambiguity is a definition of the term which is sus- 
 pected of being used in two senses ; viz. a verbal, not necessarily a 
 real definition ; as was remarked in the Compendium. 
 
 But here it may be proper to remark, that for the avoiding of 
 Fallacy or of verbal controversy, it is only requisite that the term 
 should be employed uniformly in the same sense as far as tJie existing 
 question is concerned. Thus, two persons might, in discussing the 
 question, whether Buonaparte was a great man, have some difi"erence 
 in their acceptation of the epithet "great," which would be non- 
 essential to that question ; e.g. one of them might understand by it 
 nothing more than eminent intellectual and moral qualities; while the 
 other might conceive it to imply the performance of splendid actions: 
 this abstract difi'erence of meaning would not produce any disagree- 
 ment in the existing question, because both those circumstances are 
 united in the case of Buonaparte ; but if one of the parties miderstood 
 
Chap. V.] ON FALLACIES. 73 
 
 the epithet "great" to imply generosity of character, &,c. then 
 there ivould be a disagreement. Definition, the specific for ambiguity, 
 is to be employed and demanded with a view to this principle ; it is 
 sufficient on each occasion to define a term as far as regards the 
 question in Jmnd. 
 
 Of those cases in which the ambiguity aiiaes from tJie conteoct, there 
 are many species ; several of which Logicians have enumerated, but 
 have neglected to refer them, in the first place, to one common class, 
 {viz. the one under which they are here placed ;) and have even 
 arranged some under the head of Fallacies '* in didione,'' and others, 
 *' extra didionem.'^ 
 
 We may consider, as the first of these species, the Fallacy of 
 *' Division" and that of " Composition," taken together, since in each 
 of these the middle term is used in one Premiss colledively, in the 
 other, distributively: if the former of these is the major Premiss, and 
 the latter the minor, this is called the " Fallacy of division;" the 
 term which is first taken collectively being afterwards divided ; and 
 vice versa. The ordmary examples are such as these ; all the angles 
 of a triangle are equal to two right angles: A B C, is an angle of a 
 triangle ; therefore A B C, is equal to two right angles. Five is one 
 number ; three and two are five ; therefore three and two are one 
 number: or, three and two are two numbers, five is three and two, 
 therefore five is two numbers: it is manifest that the middle tenu, 
 three and two, (in this last example,) is ambiguous, signifying, in the 
 major Premiss, "taken distinctly," in the minor, "taken together:" 
 and so of the rest. 
 
 To this head may be referred the Fallacy by which men have some- 
 times been led to admit, or pretend to admit, the doctrine of necessity; 
 i.e. he who necessarily goes or stays {i.e. in reality, " who necessarily 
 goes, or who necessarily stays'') is not a free agent ; you must neces- 
 sarily go or stay; {i.e. " you must necessarily take the alteimative,'') 
 therefore you are not a free agent. Such also is the Fallacy which 
 probably operates on most adventurers in lotteries ; e.g. the gaining of 
 a high prize is no uncommon occurrence ; and what is no uncommon 
 occurrence may reasonably be expected ; therefore the gaining of a 
 high prize "may reasonably be expected:" the conclusion when 
 applied to the individual, (as in practice it is,) must be understood in 
 the sense of " reasonably expected by a certain individual;'' therefore 
 for the major Premiss to be true, the middle term must be understood 
 to mean, "no uncommon occurrence to some owe 2^articular person;' 
 whereas for the minor (which has been placed first) to be true, you 
 must understand it of "no uncommon occurrence to some one or 
 other;" and thus you will have the FalUicy of Composition. 
 
 There is no Fallacy more common, or more likely to deceive than 
 the one now before us : the form in which it is most usually om])loycd, 
 is, to estabUsh some truth, separately, concerning cocIl single member 
 
74 ON FALLACIES. [Chap. V. 
 
 of a certain class, and thence to infer the same of the whole collectively : 
 thus some infidels have laboured to prove concerning some one of our 
 Lord's miracles, that it might have been the result of an accidental 
 conjuncture of natural circumstances ; next, they endeavour to prove 
 the same concerning another; and so on ; and thence infer that all 
 of them might have been so. They might argue in like manner, that 
 because it is not very improbable one may throw sixes in any one out 
 of a hundred throws, therefore it is no more improbable that one may 
 throw sixes a hundred times running. 
 
 This Fallacy may often be considered as turning on the ambiguity 
 of the word " all ;" which may easily be dispelled by substituting for 
 it the word "each" or '* every," where that is its signification; e.g. 
 " all these trees make a thick shade" is ambiguous, meaning, either 
 *' every one of them," or " all together." 
 
 This is a Fallacy with which men are extremely apt to deceive 
 themselves: for when a multitude of particulars are presented to the 
 mind, many are too weak or too indolent to take a comprehensive 
 view of them ; but confine their attention to each single point, by 
 turns ; and then decide, infer, and act, accordingly ; e.g. the impru- 
 dent spendthrift, finding that he is able to afi'ord this, or that, or the 
 other expense, forgets that all of them together will ruin him. 
 
 To the same head may be reduced that fallacious reasoning by 
 which men vindicate themselves to their own conscience and to others, 
 for the neglect of those undefined duties, which, though indispensable, 
 and therefore not left to our choice whether we will practise them or 
 not, are left to our discretion as to the mode, and the particular occa- 
 sions of practising them; e.g. " I am not bound to contribute to this 
 charity in particular ; nor to that ; nor to the other : ' ' the j:>r«cizca^ 
 conclusion which they draw, is, that all charity may be dispensed with. 
 As men are apt to forget that any two circumstances (not naturally 
 connected) are more rarely to be met with combined than separate, 
 though they be not at all incompatible ; so also they are apt to 
 imagine from finding that they are rarely combined, that there is an 
 incompatibility; e.g. if the chances are ten to one against a man's 
 possessing strong reasoning powers, and ten to one against exquisite 
 taste, the chances against the combination of the two (supposing them 
 neither connected nor opposed) will be a hmidred to one. Many 
 therefore, from finding them so rarely united, will infer that they are 
 in some measure incompatible ; which Fallacy may easily be exposed 
 in the form of Undistributed middle; "qualities unfriendly to each 
 other are rarely combined ; excellence in the reasoning powers and 
 in taste are rarely combined ; therefore they are qualities unfriendly 
 to each other." 
 
 § 11. The other kind of ambiguity arising from the context, and 
 which is the last case of Ambiguous middle that we shall notice, is 
 the ^'fallacia accidentis,'^ together with its converse "fallacia a dido 
 
Chap. AM ON FALLACIES. 75 
 
 secundum quid ad dictum simjyliciter;'' in eacli of which the middle 
 is used in one Premiss to signify something considered simply, in 
 itself, and as to its essence ; and in the other Premiss, so as to imply 
 that its accidents are taken into account with it : as in the well-known 
 example, " what is bought in the market is eaten ; raw meat is bought 
 in the market; therefore raw meat is eaten." Here the middle has 
 understood in conjunction with it, in the major Premiss, *' as to its 
 substance merely ; " in the minor, ' ' as to its condition and circumstances. ' ' 
 
 To this head perhaps, as well as to any, may be referred the 
 Fallacies which are frequently founded on the occasional, partial, and 
 temporary variations in the acceptation of some term, arising from 
 circumstances of person, time, and place, which Avill occasion some- 
 thing to be understood in conjunction with it beyond its strict literal 
 signification ; e.g. the phrase " Protestant ascendancy," having become 
 a kind of Avatch-word or gathering-cry of a party, the expression of 
 good wishes for it would commonly imply an adherence to certain 
 measures not literally expressed by the words ; to assume therefore 
 that one is unfriendly to " Protestant ascendancy" in the literal 
 sense, because he has declared himself unfriendly to it when implying 
 and connected with such and such other sentiments, is a gross Fallacy ; 
 and such an one as perhaps the authors of the above would much object 
 to, if it was assumed of them that they were adverse to " the cause of 
 liberty throughout the world," and to "a fair representation of the 
 people," from their objecting to join with the members of a factious 
 party in the expression of such sentiments. 
 
 Such Fallacies may fairly be referred to the present head. 
 
 § 12. Of the Non-logical (or material) Fallacies, and first of begging 
 the question. 
 
 The indistinct and unphilosophical account which has been given 
 by Logical writers of the Fallacy of " non-causd,'' and that of ^* peti- 
 tio 2^^^^cipii/' makes it very difficult to ascertain wherein they con- 
 ceived them to dilfer, and what, according to them, is the nature of 
 each ; without therefore professing to conform exactly to their mean- 
 ing, and with a view to distinctness only, which is the main point, 
 let us confine the name *' pctitio pnncip/iV to those cases in which 
 the Premiss either appears manifestly to be the same as the Conclusion, 
 or is actually proved from the Conclusion, oris such as would naturally 
 and properly so be proved ; (as if one should attempt to prove the 
 being of a God from the authority of holy writ ;) and to the other 
 class be referred all other cases, in which the Premiss (whether tlio 
 expressed or the suppressed one) is either proved false, or has no 
 sufficient claim to be received as true. Let it however be observed, 
 that in such cases (apparently) as this, we must not too hastily pro- 
 nounce the argument fallacious ; for it may be perfectly fair at the 
 commencement of an argument to assume a Premiss that is not more 
 evident than the Conclusion, or is even ever so paradoxical, provided 
 
76 ON FALLACIES. [Chap. V. 
 
 you proceed to prove fairly that Premiss : and in like manner it is 
 both usual and fair to begin by deducing your Conclusion from a 
 Premiss exactly equivalent to it; which is merely throwing the 
 proposition in question into the form in which it will be most con- 
 veniently proved. Arguing in a circle however must necessarily be 
 unfair; though it frequently is practised undesignedly; e.g. some 
 Mechanicians attempt to prove, (what they ought to lay down as 
 a probable but doubtful hypothesis,) that every particle of matter 
 gravitates equally ; " why ?" because those bodies which contain more 
 particles ever gravitate more strongly, i.e. are heavier: " but (it may 
 be urged) those which are heaviest are not always more bulky ;" " no, 
 but still they contain more particles, though more closely condensed ;" 
 *' how do you know that ?" " because they are heavier ;" " how does 
 that prove it ?" " because all particles of matter gravitating equally, 
 that mass which is specifically the heavier, must needs have the more 
 of them in the same space." 
 
 Obliquity and disguise being of course most important to the success 
 of the ijetitio princijoii, as well as of other Fallacies, the Sophist will 
 in general either have recourse to the circle, or else not venture to 
 state distinctly his assumption of the point in question, but wiU rather 
 assert some other proposition which im^Mes it ; thus keeping out of 
 sight (as a dexterous thief does stolen goods) the point in question, at 
 the very moment when he is taking it for granted : hence the frequent 
 union of this Fallacy with " ignoraHo elencM:"'' vide § 14. The 
 English language is 2)erhaps the more suitable for the Fallacy of 
 petitio jjrincipii, from its being formed from two distinct languages, 
 and thus abounding in synonymous expressions which have no resem- 
 blance in sound, and no connection in etymology ; so that a Sophist 
 may bring forward a proposition expressed in words of Saxon origin, 
 and give as a reason for it, the very same proposition stated in words 
 of Norman origin ; e.g, "to allow every man an unbounded freedom 
 of speech, must always be, on the whole, advantageous to the State ; 
 for it is highly conducive to the interest of the community, that each 
 individual should enjoy a liberty perfectly unlimited of expressing his 
 sentiments." 
 
 § 13. The next head is, the falsity, or at least, undue assumption 
 of a Premiss when it is not equivalent to, or dependent on the Con- 
 clusion ; which, as has been before said, seems to correspond nearly 
 with the meaning of Logicians, when they speak of " non causa pro 
 causa :^^ this name indeed would seem to apply a much narrower 
 class, there being one species of argiunents which are from cause to 
 effect, in which of course two things are necessary; 1st. the sufftciency 
 of the cause, 2d. its establishment ; these are the two Premises ; if 
 therefore the former be unduly assumed, we are arguing from that 
 which is not a sufficient cause as if it ivere so ; e.g. as if one should 
 contend from such a man's having been unjust or cruel, that he will 
 
Chap. V.] ON FALLACIES. 77 
 
 certainly be visited with some heavy temporal judgment, and come to 
 an untimely end. In this instance the Sophist, from having assumed 
 in the Premiss, the (granted) existence of a pretended cause, infers in 
 the conclusion the existence of the pretended effect, which we have 
 supposed to be the Question : or vice versa, the pretended effect may 
 be employed to establish the cause ; e.g. inferring sinfidness from 
 temporal calamity: but when both the pretended cause, and effect 
 are granted, i.e. granted to exist, then the Sophist will infer something 
 from their pretended connection ; i.e. he will assume as a Premiss, 
 that " of these two admitted facts, the one is the cause of the other ;" 
 as the opponents of the Reformation assumed that it was the cause 
 of the troubles which took place at that period, and thence inferred 
 that it was an evil. Such an aro-ument as either of these miu'lit 
 strictly be called " wo/i causa iDro causa;'' but it is not probable that 
 the Logical writers intended any such limitation, (which indeed would 
 be wholly unnecessary and impertinent,) but rather that they were 
 confounding together cause and reason; the sequence of Conclusion 
 from Premises being perpetually mistaken for that of ej^ed from 
 physical cause. It is indeed a very necessary caution in pJnlosojyhical 
 investigation not to assume too hastily that one thing is the cause of 
 another, when perhaps it is only an acciclentcd concomitant ; (as was 
 the case in the assiunption of the Premises of the last mentioned 
 examples:) but investigation is a perfectly distinct business from 
 cwgumentation ; and to mingle together the rules of the two, (as 
 Logical writers have generally done, especially in the present case,) 
 tends only to produce confusion in both. It may be better therefore 
 to drop the name which tends to perpetuate this confusion, and simply 
 state (when such is the case) that the Premiss is mululy assumed ; 
 i.e. without being either self-evident, or satisfactorily proved. 
 
 The contrivances by which men may deceive themselves or others, 
 in assuming Premises unduly, so that that undue assumjMon shall not 
 he perceived, (for it is in this the Fallacy consists) are of course 
 infinite. Sometimes (as was before observed) the douUful Premiss 
 is su2:>2yressed, as if it were too evident to need being proved, or even 
 stated, and as if the whole question turned on the estabhshment of 
 the other Premiss. 
 
 Thus II. Tooke proves, by an immense induction, that all particles 
 were originally nomis or verbs ; and thence concludes, that in reality 
 they are so still, and that the ordinary division of the parts of speech 
 is absurd ; keeping out of sight, as self-evident, the other Premiss, 
 which is absolutely false ; viz. that the meaning and force of a term, 
 now arid for ever, must be that, Avhich it, or its root originally bore. 
 
 Sometimes men are shamed into admitting an unfounded asser- 
 tion, by being assured, that it is so evident it would argue great 
 weakness to doubt it. In general, however, the more skilful Sophist 
 will avoid a dii^cct assertion of what he means unduly to assume ; 
 
78 ON FALLACIES. [Chap. V. 
 
 since that miglit direct the reader's attention to the consideration of 
 the question whether it be true or not, since that which is indisputable 
 does not so often need to be asserted: it succeeds better, therefore, 
 if you allude to the proposition as something curious and remarkable ; 
 just as the Royal Society were imposed on by being asked to account 
 for the fact that a vessel of water received no addition to its weight 
 by a live fish put into it ; while they were seeking for the cause, they 
 forgot to ascertain the fact, and thus admitted without suspicion a 
 mere fiction. Thus an eminent Scotch writer, instead of asserting 
 that " the advocates of Logic have been worsted and driven from the 
 field in every controversy," (an assertion, which if made, would have 
 been the more readily ascertained to be perfectly groundless,) merely 
 observes, that '* it is a circumstance not a little remarkable.^' 
 
 Frequently the Fallacy of ignoratio elenchi is called in to the aid of 
 this ; i.e. the Premiss is assumed on the ground of another propo- 
 sition, somewhat like it, having been proved; thus in arguing by 
 example, &c. the parallelism of two cases is often assumed from their 
 being in some respects alike, though perhaps they differ in the very 
 point which is essential to the argument ; e.g. from the circumstance 
 that some men of humble station, who have been well educated, are 
 apt to think themselves above low drudgery, it is argued that universal 
 education of the lower order, would beget general idleness : this argu- 
 ment rests of course on the assumption of parallelisra in the two 
 cases, viz. the past and the future ; whereas there is a circumstance 
 that is absolutely essential, in which they differ ; for when education 
 is universal it must cease to be a distinction ; which is probably the 
 very circumstance that renders men too proud for their work. 
 
 This very same Fallacy is often resorted to on the opposite side ; 
 an attempt is made to invalidate some argument from example, by 
 pointing out a difi'erence between the two cases, though they agree in 
 every thing that is essential to the question. Lastly, it may be here 
 remarked, conformably with what has been formerly said, that it will 
 often be left to your choice whether to refer this or that fallacious 
 argument to the present head, or that of Ambiguous middle; " z/* 
 the middle term is here used in this sense, there is an ambiguity ; if 
 in that sense, the proposition \% false.'''' 
 
 § 14. The last kind of Fallacy to be discussed is that of Irrelevant 
 Conclusion, commonly called igruyratio elenchi. Various kinds of 
 propositions are, according to the occasion, substituted for the one of 
 which proof is required. 
 
 Sometimes the particular for the universal ; sometimes a proposi- 
 tion with different terms : and various are the contrivances employed 
 to efi'ect and to conceal this substitution, and to make the Conclusion 
 which the Sophist has drawn, answer, practically, the same purpose 
 as the one he ought to have established. We say, *' practicaUy the 
 same purpose," because it will very often happen that some emotion 
 
Chap. V.] ON FALLACIES. 79 
 
 will be excited — some sentiment impressed on the mind — (by a dex- 
 terous employment of this Fallacy) such a:s shall bring men into the 
 disjwsUion requisite for your purpose, tliough they may not liavo 
 assented to, or even stated distinctly in their own minds the j^f^ojyod- 
 tion which it was your business to establish. Thus if a Sophist has 
 to defend one who has been guilty of some serious oft'encc, which he 
 wishes to extenuate, though he is unable distinctly to prove that it is 
 not such, yet if he can succeed in maMng the audience laugh at some 
 casual matter, he has gained practically the same point. So also if 
 any one has pointed out the extenuating circumstances in some par- 
 ticular case of offence, so as to show that it differs widely fi-om the 
 generality of the same class, the Sophist, if he find himself unable 
 to disprove these circumstances, may do away the force of them, by 
 simply referring the action to that very class, which no one can deny 
 that it belongs to, and the very name of which will excite a feeling of 
 disgust sufficient to counteract the extenuation ; e.g. let it be a case 
 of peculation, and that many mitigating circumstances have been 
 brought forward which cannot be denied ; the sophistical opponent 
 will reply, " well, but after all, the man is a rogue, and there is an 
 end of it ;" now in reality this was (by h}^)othesis) never the question ; 
 and the mere assertion of what was never denied, ought not, in fair- 
 ness, to be regarded as decisive ; but, practically, the odiousness of 
 the word, arising in great measure from the association of tlcose very 
 circumstances which belong to most of the class, but which we have 
 supposed to be absent in this particular instance, excites precisely that 
 feeling of disgust, which in efiect destroys the force of the defence. 
 In hke manner we may refer to this head all cases of improper appeals 
 to the passions, and every thing else which is mentioned by Aristotle 
 as extraneous to the matter in hand, (s^cj rQ •yrpocyy.uTo;.) 
 
 In aU these cases, as has been before observed, if the Fallacy we 
 are now treating of be employed for the apparent establishment, not 
 of the ultimate Conclusion, but (as it very commonly happens) of a 
 Premiss, {i.e. if the Premiss required be assumed on the ground that 
 some proposition resembling it has been proved,) then there will be a 
 combination of this Fallacy with the last mentioned. A good 
 instance of the employment and exposure of this Fallacy occurs in 
 Thucydides, in the speeches of Cleon and Diodotus concerning the 
 Mitylenaians : the foraier (over and above his appeal to the angry 
 passions of his audience,) urges i\\G justice of putting the revoltcrs to 
 death ; which, as the latter remarked, was nothing to the ])ur})ose, 
 since the Athenians were not sitting in judgment, but in ddiberationy 
 of wliich the proper end is crpcdicncy. 
 
 It is evident that ignoratio clenchi may be employed as well for the 
 apparent refuiatio7i of your opponent's proposition, as for the ajijiarcnt 
 establishment of your own ; for it is sul>stantially the same thing to 
 prove what was not denied, or to disj^ivve what was not asserted : 
 
so ON FALLACIES. [Chap. V. 
 
 the latter practice is not less common, and it is more offensive, 
 because it freqiientlj^ amounts to a personal affront, in attributing to 
 a person oi^inions, (fcc. wliicli he perhaps holds in abhorrence. Thus, 
 when in a discussion one party vindicates, on the ground of general 
 exj)ediency, a particular instance of resistance to Government in a 
 case of intolerable oppression, the opponent may gravely maintain 
 that " we ought not to do evil that good may come:" a proposition 
 Vv'hich of com-se had never been denied, the point in dispute being 
 " whether resistance in this particular case were doing evil or not." 
 In this example it is to be remarked, (and the remark will apply very 
 generally, ) that the Fallacy of loetitio prindpii is combined with that 
 of ignoratio elenchi, which is a very common and successful practice ; 
 viz. the Sophist proves, or disproves, not the proposition which is 
 really in question, but one which so implies it as to proceed on the 
 supposition that it is already decided, and can admit of no doubt ; by 
 this means his "assumption of the point in question" is so indirect 
 and oblique, that it may easily escape notice ; and he thus establishes, 
 practically, his Conclusion, at the very moment when he is withdraw- 
 ing your attention from it to another question. 
 
 There are certain kinds of argument recounted and named by 
 Logical writers, which we should by no means universally call Falla- 
 cies ; but which ivhen unfairly used, and so far as they are fallacious, 
 may very well be referred to the present head; such as the *■'■ argu- 
 mentum ad hominer^i,^' or personal argument, " argumentum ad 
 verecundiam,^' " argiwientum ad poj^ulum,''' &c. all of them regarded 
 as contradistinguished from " argumentum ad rem,^^ or according to 
 others (meaning probably the very same thing) " ac? judicium.'' 
 These have all been described in the lax and popidar language before 
 alluded to, but not scientifically: the '^ argumenturti ad hominerti" 
 they say, " is addressed to the peculiar circumstances, character, 
 avowed opinions, or past conduct of the individual, and therefore has 
 a reference to him only, and does not bear directly and absolutely on 
 the real question, as the ^argumentum ad rem' does:" in like manner 
 the ^'argumentum ad verecundiam" is described as an appeal to our 
 reverence for some respected authority, some venerable institution, 
 &c. and the " argumentum ad jJOjDulum," as an appeal to the preju- 
 dices, passions, &,g. of the multitude, and so of the rest. Along 
 with these is usually enumerated '^argumentum ad igno7xmtiam," which 
 is here omitted as being evidently nothing more than the employ- 
 ment of some kind of Fallacy, in the widest sense of that word, 
 towards such as are likely to be deceived by it. It appears then, 
 (to speak rather more technically,) that in the " argumentum ad homi- 
 nem" the Conclusion which actually is established, is not the absolute 
 and general one in question, but relative and particular ; viz. not that 
 *' such and such is the fact," but that " this man is bound to admit it, 
 in conformity to his principles of Reasoning, or in consistency with his 
 
Chap, v.] ON FALLACIES. 81 
 
 own conduct, situation, &;c." Such a Conclusion it is often both fair 
 and necessary to establish, in order to silence those who will not yield 
 to fair general argument ; or to convince those whose weakness and 
 prejudices would not allow them to assign to it its due weight : it is 
 thus that our Lord on many occasions silences the cavils of the Jews ; 
 as in the vindication of heahng on the Sabbath, wliicli is paralleled by 
 the authorized practice of drawing out a beast that has fallen into a 
 pit. AU this, as we have said, is perfectly fair, provided it be done 
 plainly, knowingly, and o,vowedUj; but if you attempt to suhst'dute this 
 partial and relative Conclusion for a more general one — if you 
 triumph as having established your proposition absolutely and uni- 
 versally, from having established it, in reality, only as far as it 
 relates to your opponent, then you are guilty of a fallacy of the kind 
 which we are now treating of: your Conclusion is not in reality that 
 which was, by your own account, proposed to be proved : the falla- 
 ciousness depends upon the deceit or attempt to deceive. The same 
 observations will a^jjjZ^ to '' argumcrdam ad vereciuidiam,'^ and the 
 rest. 
 
 It is very common to employ an ambiguous term for the purpose of 
 introducing the Fallacy of Irrelevant Conclusion; i.e. when you cannot 
 prove your proposition in the sense in which it was maintained, to 
 prove it in some other sense ; e.g. those who contend against the 
 efficacy of faith, usually employ that word in their arguments in the 
 sense of mere belief, unaccompanied with any moral or practical 
 result, but considered as a mere intellectual process ; and when they 
 have thus proved their conclusion, they oppose it to one in which the 
 word is used in a widely diflferent sense. 
 
 § 15. The Fallacy of ignorcdlo elenchi is no where more common 
 than in protracted controversy, when one of the parties, after having 
 attempted in vain to maintain his position, slufts his ground as 
 covertly as possible to another, instead of honestly giving up the 
 point. An instance occurs in an attack made on the system pursued 
 at one of our Universities. The objectors finding themselves unable 
 to maintain their charge of the present neglect of Mathematics in that 
 place, (to which neglect they had attributed the late general decline 
 in those studies,) they shifted their ground, and contended that that 
 University Avas never famous for Mathematicians ; which not only 
 does not establish, but absolutely overthrows their own original 
 assertion ; for if it 7ievcr succeeded in those pursuits, it could not have 
 caused their late decline. 
 
 A practice of this nature is common in oral controversy especially ; 
 vi^. mat of combating both your opponent's Premises altcrnatchj, and 
 shifting the attack from the one to the other, without waiting to have 
 either of them decided upon before you quit it. 
 
 It has been remarked above, that one class of the propositions that 
 may be, in this Fallacy, substituted for the one required, is the 
 
 G 
 
82 ON FALLACIES. [Chap. V. 
 
 particular for the universal: nearly akin to this is the very common 
 ease of proving something to be possible when it ought to have been 
 proved highly probable ; or 2-)robable, when it ought to have been proved 
 necessary; or, which comes to the very same, proving it to be not 
 necessary, when it should have been proved not 2^robable; or improbable, 
 when it should have been proved impossible. Aristotle {in Rhet. 
 Book 11.) complains of this last branch of the Fallacy, as giving an 
 undue advantage to the respondent : many a guilty person owes his 
 acquittal to this ; the jury considering that the evidence brought does 
 not demonstrate the absolute impossibility of his being innocent, 
 though perhaps the chances are innumerable against it. 
 
 § 16. Similar to this case is that which may be called the Fallacy 
 of objections ; i.e. showing that there are objections against some plan, 
 theory or system, and thence inferring that it should be rejected; 
 when that which ought to have been proved, is, that there are more, 
 or stronger objections against the receiving than the rejecting of it. 
 This is the main, and almost universal Fallacy of infidels, and is that 
 of which men should be first and principally warned. This is also 
 the stronghold of bigoted anti-innovators, who oppose all reforms and 
 alterations indiscriminately ; for there never was, nor will be, any plan 
 executed or proposed, against which strong and even unanswerable 
 objections may not be urged ; so that unless the opposite objections be 
 set in the balance on the other side, we can never advance a step. 
 " There are objections," said Dr. Johnson, " against a plenum, and 
 objections against a vacuum; but one of them must be true." 
 
 The very same Fallacy indeed is employed on the other side, by 
 those who are for overthrowing whatever is established as soon as 
 they can prove an objection against it, without considering whether 
 more and weightier objections may not lie against their own schemes : 
 but their opponents have this decided advantage over them, that they 
 can urge with great plausibility, "we do not call upon you to reject 
 at once whatever is objected to, but merely to suspend your judgment 
 and not come to a decision as long as there are reasons on both 
 sides :" now since there always will be reasons on both sides, this 
 non-decision is practically the very same thing as a decision in favour 
 of the existing state of things ; the delay of trial becomes equivalent to 
 an a^cquittal.^ 
 
 § 17. Another form of ignoratio elenchi, which is also rather the 
 most serviceable on the side of the respondent, is, to prove or disprove 
 some part of that which is required, and dwell on that, suppressing all 
 the rest. 
 
 8 " Not to resolve, is to resolve." — Ba- them not only from the perplexity of 
 
 CON. doubt and the danger of delay, but also 
 
 How happy it is for mankind that in from the pain of regret, since we acquiesce 
 
 the most momentous concerns of life their much more cheerfully in that which is 
 
 decision is generally formed /or them by unavoidable, 
 external circumstances; which thus saves 
 
Chap. V.] ON FALLACIES. 83 
 
 Thus, if a University is charged with cultivating only the mere 
 elements of Mathematics, and in reply a list of the hooks studied there 
 is produced, should even any one of those hooks he not elementary, 
 the charge is in fairness refuted ; but the Sophist may then earnestly 
 contend that some of those books are elementary ; and thus keep out 
 of sight the real question, viz. whether they are all so. 
 
 Hence the danger of ever advancing more than can be well main- 
 tained ; since the refutation of tlud will often quash the whole : a 
 guilty person may often escape by having too much laid to his charge : 
 so he may also by having too much evidence against him, i.e. some 
 that is not in itself satisfactory: thus, a prisoner may sometimes 
 obtain acquittal by showing that one of the witnesses against him is 
 an infamous informer and spy ; though perhaps if that part of the 
 evidence had been omitted, the rest would have been sutticient for 
 conviction. 
 
 Cases of this nature might very well be referred also to the Fallacy 
 formerly mentioned, of inferring the Falsity of the Conclusion from 
 the Falsity of a Premiss, which indeed is very closely allied to the 
 present Fallacy: the real question is *' whether or not this Conclusion 
 ought to he admitted;'" the Sophist confines himself to the question, 
 "whether or not it is estahllsJied by this particular argument;'' 
 leaving it to be inferred by the audience, if he has carried his point as 
 to the latter question, that the former is thereby decided. 
 
 § 18. It will readily be perceived that nothing is less conducive to 
 the success of the Fallacy in question than to state clearly, in the 
 outset, either the proposition you are about to prove, or that which 
 you ought to prove ; it answers best to begin with the Premises, and 
 to introduce a pretty long chain of argument before you arrive at the 
 Conclusion. The careless hearer takes for granted, at the beginning, 
 that this chain will lead to the conclusion required ; and by the time 
 you are come to the end, he is ready to take for granted tliat tlie 
 Conclusion which you draw is the one required ; his idea of the ques- 
 tion having gradually become indistinct. This Fallacy is greatly 
 aided by the common practice of suppressing the Conclusion and 
 leaving it to be supplied by the hearer, who is of course less likely to 
 perceive whether it be really that " which was to be proved," than if 
 it were distinctly stated. The practice therefore is at best suspicious ; 
 and it is better in general to avoid it, and to give and require a dis- 
 tinct statement of the Conclusion intended. 
 
 § 19. Before Ave dismiss the subject of Fallacies, it may not be 
 impro^'r to mention the just and ingenious remark, that Jests are 
 Fallacies ; i.e. Fallacies so palpable as not to be likely to deceive any 
 one, but yet bearing just tliat resemblance of argument which is cal- 
 culated to amuse by the contrast ; in the same manner tliat a parody 
 does, by the contrast of its levity with the serious production which 
 it imitates. There is indeed somethinix lauf!:hable even in Fallacies 
 
84 ON FALLACIES. [Chap. V. 
 
 whicli are intended for serious conviction, when they are thoroughly- 
 exposed. There are several different kinds of joke and raillery, which 
 will be found to correspond with the different kinds of Fallacy : the 
 pun (to take the simplest and most obvious case) is evidently a mock 
 argument founded on a palpable equivocation of the middle term : and 
 the rest in like manner will be found to correspond to the respective 
 Fallacies, and to be imitations of serious argument. It is probable 
 indeed that all jests, sports, or games, {'^utbia.i) properly so called, 
 will be found, on examination, to be imitative of serious transactions : 
 but to enter fully into this subject would be unsuitable to the present 
 occasion. 
 
 We shall conclude the consideration of this subject ^vith some 
 general remarks on the legitimate province of Reasoning, and on its 
 connection with Inductive philosophy, and with Rhetoric : on which 
 points much apprehension has prevailed, tending to throw obscurity 
 over the design and use of the Science under consideration. 
 
ESSAY 
 
 ON THE PROVINCE OF REASONING. 
 
 Logic being concerned with the theory of Reasoning, it is evidently 
 necessary, in order to take a correct view of this Science, that all 
 misapprehensions should be removed, relative to the occasions on which 
 the Reasoning process is employed, the purposes it has in view, and 
 the limits within which it is confined. 
 
 Simple and obvious as such questions may appear to those who 
 have not thought much on the subject, they will appear on further 
 consideration to be involved in much perplexity and obscurity, from 
 the vague and inaccurate language of many popular writers. To the 
 confused and incorrect notions that prevail respecting the Reasoning 
 process, may be traced most of the common mistakes respecting the 
 Science of Logic, and much of the unsound and unphilosophical argu- 
 mentation which is so often to be met with in the works of ingenious 
 writers. 
 
 These errors have been incidentally adverted to in the foregoing 
 part of this article ; but it may be desirable, before we dismiss the 
 subject, to offer on these points some further remarks, which could 
 not have been there introduced without too great an interruption to 
 the development of the system. Little or nothing, indeed, remains to 
 be said, that is not wijjlled in the principles which have been already 
 laid down ; but the results and applications of those principles are 
 liable in many instances to be overlooked if not distinctly pointed out. 
 These supplementary observations will neither require, nor admit of, 
 so systematic an arrangement as has hitherto been arrived at, as 
 they will be such as are suggested principall}^ by the objections and 
 mistakes of those who have misunderstood, partially, or entirely, the 
 nature of the Logical system. 
 
 Of Induction. 
 
 § L Much has been said by some writers of the superiority of the 
 Induct! vu to the Syllogistic method of seeking truth, as if tlie two 
 stood opposed to each other ; and of the advantage of substituting the 
 Organon of Bacon for that of Aristotle, <kc. tfec, wliich indicates a 
 total misconception of the nature of both. Tliere is, however, the 
 more excuse for the confusion of thought which prevails on tliis 
 subject, because eminent Logical writers have treatt-d, or at least 
 have appeared to treat, of Induction as a disthict kind of argument 
 
86 ON THE PROVINCE OF REASONING. 
 
 from the Syllogism ; whicb if it were, it certainly might he contrasted 
 with the Syllogism : or rather the whole Syllogistic theory would fall 
 to the ground, since one of the very first principles it estahlishes, is 
 that all Reasoning, on whatever subject, is one and the same process, 
 which may be clearly exhibited in the form of Syllogisms. It is 
 hardly to be supposed, therefore, that this was the meaning of those 
 Avriters ; though it must be admitted that they have countenanced the 
 error in question, by their inaccurate expressions. This inaccuracy 
 seems chiefly to have arisen from a vagueness in the use of the word 
 Induction, which is sometimes employed to designate the process of 
 investigation and of collecting facts ; sometimes the deducing of an 
 inference from those facts. The former of these processes [i.e. that 
 of observation and experiment) is undoubtedly distinct from that which 
 takes place in the Syllogism ; but then it is not a process of argument; 
 the latter again is an argumentative process ; but then it is, like aU 
 other arguments, capable of being Syllogistically expressed. And 
 hence Induction has come to be regarded as a distinct kind of 
 argument from the Syllogism. This Fallacy cannot be more concisely 
 or clearly stated, than in the technical form with which we may now 
 presume our readers to be familiar. 
 
 Induction is distinct from Syllogism : 
 
 Induction is a process of Reasoning ; therefore 
 
 There is a process of Reasoning distinct from Syllogism. 
 
 Here, "Induction," which is the middle term, is used in different 
 senses in the two Premises. 
 
 In the process of Reasoning by which we deduce, from our observa- 
 tion of certain known cases, an inference Avith respect to unknown 
 ones, we are employing a Syllogism in Barbara with the major ^ 
 Premiss suppressed ; that being always substantially the same, as it 
 asserts that ' ' what belongs to the individual or individuals we have 
 examined, belongs to the whole class under which they come:" e.g. 
 from an examination of the history of several tyrannies, and finding 
 that each of them was of short duration, we conclude that " the same 
 is likely to be the case with all tyrannies:" the suppressed major 
 Premiss being easily supplied by the hearer; viz. '* that what belongs 
 to the tyrannies in question is likely to belong to all." 
 
 Induction, therefore, so far forth as it is an argument, may of course 
 be stated Syllogistically ; but so far forth as it is a 2^'^ocess of inquiry 
 with a view to obtain the Premises of that argument, it is of course 
 out of the province of Logic Whether the Induction (in this last 
 sense) has been sufficiently ample, i.e. takes in a sufficient number of 
 individual cases, — whether the character of those cases has been 
 correctly ascertained — and how far the individuals we have examined 
 are likely to resemble, in this or that circumstance, the rest of the class, 
 
 ^ Not the minor, aa Aldrich represents it. 
 
ON THE PROVINCE OF REASONING. 87 
 
 (fee. (fee. are points that require indeed great judgment and caution; 
 but this judgment and caution are not to be aided by Logic, because 
 they are, in reality, employed in deciding whether or not it is fair and 
 allowable to lay down your Premises; i.e. whether you are authurizcd 
 or not, to assert that "what is true of the individuals you have 
 examined, is true of the whole class:" and that this or that is true 
 of those individuals. Now the rules of Loffic have nothing: to do with 
 the truth or falsity of the Premises, but merely teach us to decide 
 (not whether the Premises are fairly laid down, but) whether the 
 Conclusion follows fairly fro7n the Premises or not. 
 
 Whether the Premises may fairly be assumed, or not, is a point 
 which cannot be decided without a competent knowledge of the nature 
 of the subject^ e.g. in Natural Philosophy, in which the circumstances 
 which in any case affect the result, are usually far more clearly ascer- 
 tained, a single instance is often accounted a sufficient Induction : e.g. 
 having once ascertained that an individual magnet will attract iron, 
 we are authorized to conclude that this property is universal : in the 
 affairs of human life, a much fuller induction is required ; as in the 
 former example. In short, the degree of evidence for any proposition 
 we originally assume as a Premiss, (whether the expressed, or the 
 suppressed one,) is not to be learned from Logic, nor indeed from any 
 one distinct Science ; but is the province of whatever Science furnishes 
 the subject matter of your argument. None but a Politician can 
 judge rightly of the degree of evidence of a proposition in Politics ; a 
 Naturahst, in Natural History, &c. he. e.g. from examination of many 
 horned animals, as sheep, cows, <kc. a Naturalist finds that they have 
 cloven feet ; now his skUl as a Naturalist is to be sho>vn in judging 
 whether these animals are likely to resemble in the form of their feet 
 all other horned animals ; and it is the exercise of this judgment, 
 too;ether with the examination of individuals, that constitutes what is 
 usually meant by the Inductive j^f^ocess; which is that by which we 
 gain 7ieiv truths, and which is not connected with Logic ; being not 
 what is strictly called lieasoning, but Investigation. But when this 
 major Premiss is granted him, and is combined with the minor, viz. 
 that the animals he has examined liave cloven feet, then he draws the 
 conclusion Logiccdly: viz. that " the feet of all horned animals are 
 cloven." Again, if from several times meeting with ill-luck on a 
 Friday, any one concluded that Friday, universally, is an unlucky 
 day, one would object to his Induction ; and yet it would not be, as 
 an argument, illogical; since the conclusion /u//oirs fairly, if yon grant 
 his implied Premiss, that the events which happened on those partic- 
 ular Fridays are such as must happen on all Fridays ; but wo sliould 
 object to his laying down this Premiss; and then-fore should justly 
 say that his Induction was faulty, tliough his argument was correct. 
 
 And here it may be remarked that tlie ordinary rule for fair argu- 
 ment, viz. that in an Enthymcme the suppressed Premiss should bo 
 
88 ON THE PROVINCE OF REASONING. 
 
 always the one of whose truth least doubt can exist, is not observed in 
 Induction ; for the Premiss which is usually the more doubtful of the 
 two, is, in that, the major ; it being in few cases quite certain that 
 the individuals respecting which some point has been ascertained are 
 to be fairly regarded as a sample of the whole class ; the major 
 Premiss nevertheless is seldom expressed, for the reason just given, 
 that it is easily understood, as being mutatis mutandis^ the same in 
 every Induction. 
 
 What has been said of Induction will equally apply to Example, 
 which differs from it only in having a singular instead of a general 
 conclusion: e.g. in the instance above, if the conclusion had been 
 drawn, not respecting tyrannies in general, but respecting this or that 
 tyranny, that it was not likely to be lasting, each of the cases adduced 
 to prove this, would have been called an Example. 
 
 On the Discovery of Truth. 
 
 § 2. Whether it is by a process of Reasoning that New Truths 
 are brought to light, is a question which seems to be decided in the 
 negative by what has been already said, though many eminent writers 
 seem to have taken for granted the affirmative. It is perhaps, in a 
 great measure, a dispute concerning the use of words ; but it is not 
 for that reason either uninteresting or unimportant, since an inaccurate 
 use of language may often, in matters of Science, lead to confusion of 
 thought, and to erroneous conclusions. And in the present instance 
 much of the undeserved contempt which has been bestowed on the 
 Logical system may be traced to this source ; for when any one has 
 laid down that "Reasoning is important in the discovery of Truth," 
 and that " Logic is of no service in the discovery of truth," each of 
 which propositions is true in a certain sense of the terms employed, 
 but not in the same sense ; he is naturally led to conclude that 
 there are processes of Reasoning to which the Syllogistic theory does 
 not apply, and of course to misconceive altogether the nature of the 
 Science. 
 
 In maintaining the negative side of the above question, three things 
 are to be premised : first, that it is not contended that Discoveries of 
 any kind of Truth can be made (or at least are usually made) without 
 Reasoning ; only that Reasoning is not the whole of the process, nor 
 the whole of that which is important therein : secondly, that Reasoning 
 shall be taken in the sense, not of every exercise of the Reason, but 
 of Argumentation, in which we have all along used it, and in which it 
 has been defined by aU the Logical writers, viz. " from certain granted 
 propositions to infer another proposition as the consequence of them:" 
 thirdly, that by a "New Truth," be understood something neither 
 expressly nor virtually asserted before, — not implied and involved in 
 any thing already known. 
 
 To prove then this point demonstratively becomes in this manner 
 
ON THE PROVINCE OF REASONING. 89 
 
 perfectly easy ; for since all Reasoning (in the sense above defined) 
 may be resolved into Syllogisms ; and since even the objectors to 
 Logic make it a subject of complaint, that in a Syllogism the Premises 
 do \'irtually assert the Conclusion, it follows at once that no New 
 Truth (as above defined) can be elicited by any process of Reasoning. 
 
 It is on this ground indeed, that the justly celebrated author of tho 
 Philosophy of Rhetoric objects to the Syllogism altogether, as neces- 
 sarily involving a petitio j^f^incipii; an objection which, of course, he 
 would not have been disposed to bring forward, had he perceived that, 
 ■whether well or ill founded, it lies against all arguments whatever. 
 
 Had he been aware that a Syllogism is no distinct kind of argument 
 otherwise than in form, but is, in fact, any argument whatever stated 
 regularly and at full length, he would have obtained a more correct 
 view of the object of all Reasoning, which is merely to expand and 
 unfold the assertions wrapt up, as it were, and implied in those with 
 which we set out, and to bring a person to perceive and acknowledge 
 the full force of that which he has admitted, — to contemplate it in 
 various points of view, — to admit in one shape what he has already 
 admitted in another, and to give up and disallow whatever is incon- 
 sistent with it. 
 
 Nor is it always a very easy task even to bring before the mind the 
 several bearings, — the various applications, — of any one proposition. 
 A common term comprehends several, often numberless individuals, 
 and these often, in some respects, widely difleriug from each other; 
 and no one can be, on each occasion of his employing such a term, 
 attendino' to and fixino; his mind on each of the individuals, or even of 
 the species so comprehended. It is to be remembered too, that both 
 Division and Generalization are in a great degree arbitrary; i.e. that 
 we may both divide the same genus on several different principles, 
 and may refer the same species to several different classes, according 
 to the nature of the discourse and drift of the argument ; each of 
 which classes will furnish a distinct middle term for an argument, 
 according to the question: e.g. if we wished to prove that *' a horse 
 feels," (to adopt an ill-chosen example from the above writer,) we 
 might refer it to the genus "animal;" to prove that "it has only a 
 single stomach," to the genus of "non-ruminants;" to prove that it 
 is "likely to degenerate in a very cold climate," we should class it 
 with "original productions of a hot climate, <fcc. ike." Now each of 
 these, and numberless others to which the same thing might be 
 referred, are implied by the very term "horse;" yet it cannot be 
 expected that they all be at once present to tho mind whenever that 
 term is uttered. Much less, when instead of such a term as that, wo 
 are employing terms of a very abstract, and perhaps complex signifi- 
 cation,^' as " government, justice, <fec." 
 
 2 On this point thoro arc some valuable remarks in the Philosophy 0/ Rhetoric itself. 
 Book IV. Ch. VII. 
 
90 ON THE PROVINCE OF REASONING. 
 
 The ten Categories ^ or Predicaments wliicli Aristotle and other 
 Logical writers have treated of, being certain general heads or summa- 
 genera, to one or more of which every term may be referred, serve the 
 pm'pose of marking out certain tracks, as it were, which are to be 
 pursued in searching for middle terms in each argument respectively ; 
 it being essential that we should generahze on a right principle, with 
 a view to the question before us ; or, in other words, that we should 
 abstract that portion of any object presented to the mind, which is 
 important to the argument in hand. There are expressions in common 
 use which have a reference to this caution ; such as ''this is a ques- 
 tion, not as to the nature of the object, but the magnitude of it:" 
 *' this is a question of time, or of place, (fee.;" i.e. " the subject must 
 be referred to this or to that Category." 
 
 With respect to the meaning of the terms in question, " Discovery," 
 and "New Truth;" it matters not whether we confine ourselves to 
 the narrowest sense, or admit the widest, provided we do but distin- 
 guish; there certainly are two kinds of "New Truth," and of 
 "Discovery," if we take those words in the widest sense in which 
 they are ever used. First, such Truths as were, before they were 
 discovered, absolutely unknown, being not imjolied by any thing we 
 previously knew, though we might perhaps suspect them as probable ; 
 such are all matters of fact strictly so called, when first made known 
 to one who had not any such previous knowledge, as would enable him 
 to ascertain them a priori; i.e. by Reasoning ; as if we inform a man 
 that we have a colony at Botany Bay ; or that the earth is at such a 
 distance from the sun ; or that platina is heavier than gold. The 
 communication of this kind of knowledge is most usually and most 
 strictly called information: we gain it from observation, and from 
 testimony; no mere internal workings of our own minds, (except when 
 the mind itself is the very object to be observed,) or mere discussions 
 in words, will make these known to us ; though there is great room for 
 sagacity in judging what testimony to admit, and forming conjectures 
 that may lead to profitable observation, and to experiments with a view 
 to it. The other class of Discoveries is of a very diff'erent nature ; 
 that which may be elicited by Reasoning, and consequently is imphed 
 in that which we already know, we assent to on that ground, and not 
 from observation or testimony : to take a Geometrical truth upon trust, 
 or to attempt to ascertain it by observation, w^ould betray a total 
 ignorance of the nature of the Science. In the longest demonstration 
 the Mathematical teacher seems only to lead us to make use of our 
 
 3 The Categories enumerated by Aris- enlarged, as it is evident may easily be 
 
 totle, are evtrla, Ttixrov, frolov, v^oa-rt, ^ov, frort, done by subdividing some of the heads ; 
 
 Ki7ird<x.i, ixi"',^t>i''-'y, 'ra.irxtii'i which are u^u- and by others curtailed, as it is no less 
 
 ally rendered, as adequately as perhaps evident that all may ultimately be referred 
 
 they can be in our language. Substance, to the two heads of Substance and Attri- 
 
 Qu'antity, Quality, Relation, Place, Time, bute, or in the language of some Logicians, 
 
 Situation, Possession, Action, Suffering. Accident. 
 The catalogue has been by some writers 
 
ON THE PROVINCE OF REASONING. 91 
 
 own stores, and point out to us how much we had already admitted ; 
 and in the case of many Ethical propositions, we assent at first 
 hearing, though perhaps we had never heard or thought of the propo- 
 sition before ; so also do Ave readily assent to the testimony of a respect- 
 able man who tells us that our troops have gained a victory ; hut 
 how different is the nature of the assent in the two cases. In 
 the latter, we are ready to thank the person for his information, as 
 being such as no Avisdom or learning would have enabled us to ascer- 
 tain ; in the former Ave usually exclaim ''very true!'' "that is a 
 valuable and just remark ; that never struck me before ! ' ' implying at 
 once our practical ignorance of it, and also our consciousness that we 
 possess, in A\'hat Ave already knoAv, the means to ascertain the truth of it. 
 
 To all practical purposes, indeed, a Truth of this description may 
 be as completely unknown to a man as the other ; but as soon as it is 
 set before him, and the argument by Avhich it is connected with his 
 previous notions is made clear to him, he recognises it as something 
 conformable to, and contained in his former belief. 
 
 It is not improbable that Plato's doctrine of Reminiscence arose 
 from a hasty extension of what he had observed in this class, to all 
 acquisition of knowledge AA'hatever. 
 
 His Theory of ideas served to confound together matters of fact 
 respecting the nature of things, (AA^hich may be perfectly ncAv to us,) 
 with propositions rdatijig to our ovm notions, and modes of thought ; 
 (or to speak perhaps more correctly, our OAvn arbitrary signs) which 
 propositions must be contained and implied in those very complex 
 notions themselves ; and whose truth is a conformity, not to the nature 
 of things, but to our own hypothesis. Such are all propositions in 
 pure Mathematics, and many in Ethics, viz. those which involve no 
 assertion as to real matters of fact. It has been rightly remarked, 
 that Mathematical propositions are not properly true or false in the 
 same sense as any proposition respecting real fact is so called ; and 
 hence the truth (such as it is) of such propositions is necessary and 
 eternal ; since it amounts only to this, that any complex notion Avhich 
 you have arbitrarily framed, must be exactly conformable to itself. 
 The proposition that "the belief in a future state, combined with a 
 complete dcA-otion to the present life, is not consistent Avith the 
 character of prudence," Avould be not at all the less true if a future 
 state were a chimera, and prudence a quahty Avhich Avas nowhere met 
 with ; nor would the truth of the j\Iathcmatician's conclusion bo 
 shaken, that "circles are to each other as the squares of their diam- 
 eters," should it be found that there never had been a circle or a 
 square, conformable to the definition, in rcrum naturd. 
 
 The Ethical proposition just instanced, is one of those which 
 Locke calls " trifling," because the Predicate is merely a part of the 
 complex idea implied by the subject; and he is right, if by "trilling" 
 he means that it gives not, strictly speaking, any infonnation; but ho 
 
92 ON THE PROVINCE OF REASONING. 
 
 should consider that to remind a man of what he had not, and what 
 he would have thought of, may be, practically, as valuable as giving 
 him information ; and that most propositions in the best sermons, and 
 all in pure Mathematics, are of the description which he censures. 
 
 It is indeed rather remarkable that he should speak so often of 
 building Morals into a demonstrative Science, and yet speak so 
 slightingly of those very propositions to which we must absolutely 
 confine ourselves, in order to give to Ethics even the appearance of 
 such a Science ; for the instant you come to an assertion respecting 
 a maiter offojCt, as that '* men ( i.e. actually existing men) are bound 
 to practise virtue," or ** are liable to many temptations," you have 
 stepped off the ground of strict demonstration, just as when you 
 2)roceed to practical Geometry. 
 
 But to return : it is of the utmost importance to distinguish these 
 two kinds of Discovery of Truth ; to the former, as we have said, the 
 word " informMion'' is most strictly applied; the communication of 
 the latter is more properly called "instruction.'" We speak of the 
 usu£tl practice ; for it would be going too far to pretend that writers 
 are uniform and consistent in the use of these, or of any other term. 
 We say that the Historian gives us hiformation respecting past times; 
 the Traveller, respecting foreign countries : on the other hand, the 
 Mathematician gives indructioii in the principles of his Science ; the 
 Moralist i7istrvAts us in our duties ; and we generally use the expres- 
 sions "a well-informed man," and "a well-instructed man," in a 
 sense conformable to that which has been here laid down. However, 
 let the words be used as they may, the things are evidently different, 
 and ought to be distinguished. It is a question comparatively unim- 
 portant, whether the term "Discovery" shall or shall not be extended 
 to the eliciting of those Truths, which, being implied in our previous 
 knowledge, may be established by mere strict Reasoning. Similar 
 verbal questions indeed might be raised respecting many other cases: 
 e.g. one has forgotten {i.e. cannot recollect) the name of some person 
 or place ; perhaps we even try to think of it, but in vain ; at last 
 some one reminds us, and we instantly recognise it as the one we 
 wanted to recollect ; it may be asked, was this in our mind or not ? 
 The answer is, that in one sense it was, and in another sense, it was 
 not. Or, again, suppose there is a vein of metal on a man's estate 
 which he does not know of; is it part of his possessions or not ? and 
 when he finds it out and works it, does he then acquire a n£,w 
 possession or not ? Certainly not, in the same sense as if he has a 
 fresh estate bequeathed to him, which he had formerly no right to ; 
 but to all practical purposes, it is a new possession. This case indeed 
 may serve as an illustration of the one we have been considering ; and 
 in all these cases, if the real distinction be understood, the verbal 
 question will not be of much consequence. To use one more illustra- 
 tion ; Reasoning has been aptly compared to the piling together blocks 
 
ON THE PROVINCE OF REASONING. 93 
 
 of Stone ; on each of which, as on a pedestal, a man can raise himself 
 a small, and but a small, height above the plain ; but wliieli, wlien 
 skilfully built up, will form a flight of steps, which will raise him to 
 a great elevation. Now (to pursue this analogy) when the materials 
 are all ready to the builder's hand, the blocks ready dug and broiiglit, 
 his work resembles one of the two kinds of Discovery just mentioned, 
 viz. that to which we have assigned the name of iyistruction : but 
 if his materials are to be entirely, or in part, provided by himself, — 
 if he himself is forced to dig fresh blocks from the quarry, — this 
 corresponds to the other kind of Discovery. 
 
 We have hitherto spoken of the employment of argument in the 
 establishment of those hypothetical Truths (as they may be called) 
 which relate only to our own abstract notions ; it is not, however, 
 meant to be insinuated that there is no room for Reasoning in the 
 estabhshment of a matter of fact ; but the other class of Truths have 
 first been treated of, because in discussing subjects of that kind the 
 process of Reasoning is always the ^9n?zc?}MZ, and often the cmly 
 thing to be attended to, if we are but certain and clear as to the 
 meaning of the terms ; whereas, when assertions respecting real 
 existence are introduced, we have the additional and more important 
 business of ascertaining and keeping in mind the degree of evidence 
 for those facts, since, otherwise, our Conclusions could not be relied 
 on, however accurate our Reasoning ; but, undoubtedly, we may by 
 Reasoning arrive at matters of fact, if we have matters of fact to set 
 out vjith as data; only that it will very often happen that "from 
 certain facts," as Campbell remarks, " we draw only probable Con- 
 clusions;" because the other Premiss introduced (which he over- 
 looked) is only probable. He observed that in such an instance, for 
 example, as the one lately given, we infer from the certainty that 
 such and such tyrannies have been short-lived, the prohtdnliti/ that 
 others will be so ; and he did not consider that there is an understood 
 Premiss which is essential to the argument ; {viz. that all tyrannies 
 will resemble those we have already observed,) which being only of a 
 probable character, must attach the same degree of uncertainty to 
 the Conclusion. An individual fact is not unfrequently elicited by 
 skilfully combining, and Reasoning from, those already known ; of 
 which many curious cases occur in the detection of criminals by 
 officers of justice, and J>arristers, who acquire by practice such 
 dexterity in that particular department, as sometimes to draw the 
 right Conclusion from data, which might be in the possession of 
 others, without being applied to the same use. In all cases of tho 
 estabhshment of a general fact from Induction, that general fact (as 
 has been formerly remarked) is ultimalely established by Reasoning ; 
 e.g. Bakewcll, the celebrated cattle-breeder, observed, in a great 
 number of individual beasts, a tendency to fatten readily, and in a 
 great number of others the absence of this constitution ; in every 
 
94 ON THE PROVINCE OF REASONING. 
 
 individual of the former description, lie observed a certain peculiar 
 make, tliough tliey differed widely in size, colour, &c. Those of the 
 latter description differed no less in various points, but agreed in 
 being of a different make from the others : these facts were his data ; 
 from which, combining them Avitli the general principle that Nature 
 is steady and uniform in her proceedings, he Logically drew the con- 
 clusion that beasts of the specified make have universally a peculiar 
 tendency to fattening: but then his principal merit consisted in 
 making the observations, and in so combining them as to abstract 
 from each of a multitude of cases, differing widely in many respects, the 
 circumstances in which they aU agreed ; and also in conjecturing 
 skilfully how far those circumstances were hkely to be found in the 
 whole class ; the making such observations, and still more the com- 
 bination, abstraction, and judgment employed, are what men commonly 
 mean (as was above observed) when they speak of Induction ; and 
 these operations are certainly distinct from Reasoning. The same 
 observations will apply to numberless other cases, as, for instance, to 
 the Discovery of the law of "m inertice,'' and the other principles of 
 Natural Philosophy. 
 
 But to what class, it may be asked, should be referred the Dis- 
 coveries thus made ? All would agree in calling them, when first 
 ascertained, "New Truths," in the strictest sense of the word; which 
 would seem to imply their belonging to the class which may be called, 
 by way of distinction, ''Physical Discoveries:'^ and yet their being 
 ultimately established by Reasoning, would seem, according to the 
 foregoing rule, to refer them to the other class, viz. what may be 
 called "Logical Discoveries;" since whatever is established by 
 Reasoning, must have been contained and virtually asserted in the 
 Premises. In answer to this, it is to be observed, that they certainly 
 do belong to the latter class, relatively, to a person who is in possession 
 of the data ; but to him wdio is not, they are New Truths of the other 
 class; for it is to be remembered, that the words " Discovery " and 
 *' New Truths " are necessarily relative : there may be a proposition 
 which is to one person absolutely known ; to another, {viz. one to 
 whom it has never occurred, though he is in possession of all the data 
 from which it may be jwoved) it will be, when he comes to perceive 
 it, by a process oi instru^ion, what we have called a Logical Discovery ; 
 to a third, {viz. one who is ignorant of these data,) it will be absolutely 
 unknown, and w^ill have been, when made known to him, a perfectly 
 and properly New Truth, — a piece of information, — a Physical 
 Discovery as we have called it. To the Philosopher, therefore, who 
 arrives at the Discovery by Reasoning from his observations, and 
 from established principles combined with them, the Discovery is of 
 the former class ; to the multitude, probably of the latter, as they will 
 have been most likely not possessed of all his data. It follows from 
 what has been said, that in Mathematics, and in such Ethical pro- 
 
ON THE PROVINCE OF REASONING. 95 
 
 positions as we were lately speaking of, we do not allow the possibility 
 of any but a Logical Discovery ; i.e. no proposition, of that class, can 
 be true, which was not implied in the definitions we set out with, 
 which are the first principles: for since these propositions do not 
 profess to state any matter of fact, the only Truth they can possess, 
 consists in conformity to the original principles ; to one, therefore, 
 who knoivs these principles, such propositions are Truths already 
 implied, since they may be developed to him by Reasoning, if he is 
 not defective in the discursive faculty ; to one who does not under- 
 stand those principles, {i.e. is not master of the definitions) such 
 propositions are absolutely unmeaning. On the other hand, proposi- 
 tions relating to matters of fact, 7nay be, indeed, implied in wliat he 
 already knew ; (as he who knows the climate of the Alps, the Andes, 
 (fee. (fee. has virtually admitted the general fact, that *' the tops of 
 mountains are comparatively cold ; ") but as these possess an absolute 
 and physical Truth, they may also be absolutely "new," their Truth 
 not being implied by the mere terms of the jyivpositions. The truth 
 or falsity of any proposition concerning a triangle, is implied by the 
 meaning of that and of the other Geometrical terms ; wliereas, 
 though one may understand (in the ordinary sense of that word) the 
 full meaning of the terms, "moon " and " inhabited," and of all the 
 other terms in the language, he cannot thence be certain that the 
 moon is, or is not, inhabited. 
 
 It has probably been the source of much perplexity that the terra 
 "^rwe" has been applied indiscriminately to two such different 
 classes of propositions. The term definition is used with the same 
 laxity ; and much confusion has thence resulted. 
 
 Such Definitions as the Mathematical, must imply every attribute 
 that belongs to the thing defined ; because that thing is merely our 
 meaning, which meaning the Definition lays down ; whereas, real 
 substances, having an independent existence, may possess innumerable 
 qualities (as Locke observes) not implied by the meaning we attach 
 to their names, or, as Locke expresses it, by our ideas of them. 
 " Their nominal essence (to use his language) is not the same as their 
 real essence: " whereas the nominal essence, and the real essence, of 
 a circle, (fee. are the same. A Mathematical Definition, therefore, 
 cannot properly be called true, since it is not properly a j^'ojwsiiion, 
 (anymore than an article in a Dictionary,) but merely an explanation 
 of the meaning of a term. Perhaps in Definitions of this class, it 
 might be better to substitute (as Aristotle usually docs) the imperative 
 mood for the indicative ; thus bringing them into the form of postu- 
 lates ; for the Definitions and the postulates in Mathematics ditier in 
 little or nothing but the form of expression; e.g. "let a four-sided 
 figure, of equal sides and right angles, be called a S(iuare," would 
 clearly imply that such a figure is conceivable, and that the writer 
 intended to employ that term to signify such a figure ; which is 
 
96 ON THE PROVINCE. OF REASONING. 
 
 precisely all tliat is intended to be asserted. If, indeed, a Mathe- 
 matical writer means to assert that the ordinary meaning of the 
 term is that which he has given, that, certainly, is a proposition, 
 which must be either true or false ; but in defining a new term, the 
 term indeed may be ill-chosen and improper, or the Definition may 
 be self-contradictory, and consequently unintelligible ; but the words, 
 " true," and " false," do not apply. The same may be said of what 
 are called nominal Definitions of other things, i.e. those which merely 
 explain the meaning of the word ; viz. they can be true or false only 
 when they profess (and so far as they profess) to give the ordinary 
 and established meaning of the term. But those which are called 
 real Definitions, viz. which unfold the nature of the thing, (which they 
 may do in various degrees,) to these the epithet " true " may be 
 applied ; and to make out such a Definition will often be the very end 
 (not as in Mathematics the beginning) of our study. 
 
 In Mathematics there is no such distinction between nominal and 
 real Definition; tlie meaning of the term, and the nature of the thing, 
 being one and the same : so that no correct Definition whatever of any 
 Mathematical term can be devised, which shall not imply every thing 
 which belongs to the term. 
 
 When it is asked, then, whether such great Discoveries, as have 
 been made in Natural Philosophy, were accomplished, or can be 
 accomplished by Reasoning ? the inquirer should be reminded, that 
 the question is ambiguous ; it may be answered in the affirmative, if 
 by " Reasoning " is meant to be included the assumption of Premises ; 
 to the right performance of that work, is requisite, not only in many 
 cases, the ascertainment of facts, and of the degree of evidence for 
 doubtful propositions, (in which observation and experiment wiU often 
 be indispensable,) but also a skilful selection and combination of known 
 facts and principles ; such as implies, amongst other things, the 
 exercise of that powerful abstraction which seizes the common circum- 
 stances — the point of agreement — in a number of, otherwise dissimilar, 
 individuals: it is in this that the greatest genius is shown. But if 
 " Reasoning " be understood in the limited sense in which it is usually 
 defined, then we must answer in the negative ; and reply that such 
 Discoveries are made by means of Reasoning combined with other 
 operations. 
 
 In the process we have been speaking of, there is much Reasoning 
 throughout ; and thence the whole has been carelessly called a " Pro- 
 cess of Reasoning." 
 
 It is not, indeed, any just ground of complaint that the word 
 Reasoning is used in two senses ; but that the two senses are per- 
 petually confounded together: and hence ^t is that some Logical 
 writers fancied that Reasoning {viz. that which Logic treats of) was 
 the method of discovering Truth ; and that so many other writers 
 have accordingly complained of Logic for not accomplishing that end, 
 
ON THE PROVINCE OF REASONING. 07 
 
 urging that ** Syllogism " {i.e. Reasoning, though they overlooked 
 the coincidence) never established any thing that is, strictly speaking, 
 unknown to him who has granted the Premises : and proposing the 
 introduction of a certain " rational Logic " to accomplish this pur- 
 pose ; i.e. to direct the mind in the progress of investigation. Sup- 
 posing that some such system could he devised — that it could even be 
 brought into a Scientific form, (which he must be more sanguine than 
 Scientific Avho expects,) that it were of the greatest conceivable utility, 
 and that it should be allowed to bear the name of " Logic," since it 
 would not be worth while to contend about a word, still it would not 
 as these writers seem to suppose, have the same object proposed with 
 the Aristotelian Logic ; nor be in any respect a rival to that system. 
 A 2^lougli may be a much more ingenious and valuable instrument than 
 nfiml, but it never can be substituted for it. 
 
 Those Discoveries of general laws of Nature, (fcc, of which we have 
 been speaking, being of that character which we have described by 
 the name of " Logical Discoveries," to him ivho is in j)OSScsslon of all 
 the Premises from ivhich they are deduced; but being, to the multitude 
 (who are unacquainted with many of those Premises) strictly " New 
 Truths;" hence it is, that men in general give to the general facts, 
 and to them, most peculiarly, the name of Discoi^eries ; for to thcra- 
 selves they are such, in the strictest sense ; the Premises fi-om which 
 they were inferred being not only orighially unkno^vn to them, but 
 frequently remaining unknown to the very last: e.g. the general con- 
 clusion concerning cattle, which Bakewell made known, is what most 
 Agriculturists (and many others also) are acquainted with ; but the 
 Premises he set out with, viz. the facts respecting this, that, and the 
 other, individual ox, (the ascertainment of which facts was his first 
 Discovery) these are what few know, or care to know, with any exact 
 particularity. 
 
 And it may be added, that these discoveries of particular facts, 
 which are the immediate result of observation, are, in themselves, 
 uninteresting and insignificant, till they are combined so as to lead to 
 a grand general result; those who on each occasion watclied the 
 motions, and registered the date of a comet, little thought, perhaps, 
 themselves, what magnificent results they were preparing the way for. 
 So that there is an additional cause which has confined the term Dis- 
 covery to these grand general conclusions ; and, as was just observeil, 
 they are, to the generality of men, perfectly New Truths in the 
 strictest sense of the word, not being implied in any previous know- 
 ledge they possessed. Very often it Avill happen, indeed, that the 
 conclusion thus drawn will amount only to ii }wohahle conjecture; which 
 conjecture will dictate 1«o the inquirer such an experivient, or course 
 of experiments, as will fully establish the fact ; thus Sir H. Davy, 
 from finding that the fiame of hydrogen gas was not cuninHinicatcd 
 through a long slender tube, conjectured that a shorter, but still 
 
 H 
 
98 ON THE PROVINCE OF REASONING. 
 
 slenderer tube, would answer the same purpose ; this led him to try 
 the experiments, in which, by continually shortening the tube, and at 
 the same time lessening its bore, he arrived at last at the wire-gauze 
 of his safety-lamp. 
 
 It is to be observed also, that whatever credit is conveyed by the 
 word *' Discovery," to him who is regarded as the author of it, is well 
 deserved by those who skilfully select and combine known Truths, 
 {especially such as have been long and generally known,) so as to 
 elicit important, and hitherto unthought-of, conclusions ; theirs is the 
 master mind ; u^x^nKroutx,'^ (p^ouviaig' whereas men of very inferior 
 powers may sometimes, by immediate observation, discover perfectly 
 new facts, empirically, and thus be of service in furnishing materials 
 to the others ; to whom they stand in the same relation (to recur to a 
 former illustration) as the brickmaker or stonequarrier, to the architect. 
 It is peculiarly creditable to Adam Smith, and to Malthus, that the 
 data from Avhich they drew such important Conclusions had been in 
 every one's hands for centuries. 
 
 As for Mathematical Discoveries, they (as we have before said) 
 must always be of the description to which we have given the name 
 of " Logical Discoveries ; " since to him who properly comprehends 
 the meaning of the Mathematical terms, (and to no other are the 
 Truths themselves, properly speaking, intelligible,) those results are 
 im2)lied in his previous knowledge, since they are Logically deducible 
 therefrom. It is not, however, meant to be implied, that Mathemor- 
 tical Discoveries are effected by pure Reasoning, and by that singly. 
 For though there is not here, as in Physics, any exercise of judgment 
 as to the degree of evidence of the Premises, nor any experiments and 
 observations, yet there is the same call for skill in the selection and 
 combination of the Premises in such a manner as shall be best calcu- 
 lated to lead to a new, that is, unjperceived and untlmugM-of Conclu- 
 sion. 
 
 In following, indeed, and taking in a demonstration, nothing is 
 called for but pure Reasoning ; but the assumption of Premises is not 
 a loart of Reasoning, in the strict and technical sense of that term. 
 Accordingly, there are many who c^n follow a demonstration, or any 
 other train of argument, who would not succeed weU in framing one 
 of their own.^ 
 
 For both kinds of Discovery then, the Logical, as weU as the 
 Physical, certain operations are requisite, beyond those which can 
 fairly be comprehended under the strict sense of the word " Reason- 
 ing ; " in the Logical, is required a skilful selection and combination 
 of known Truths; in the Physical we must employ, in addition 
 (generally speaking) to that process, observation and experiment. It 
 will generally happen, that in the study of Nature, and, miiversally, 
 
 * Hence the Student must not confine himself to this passive kind of employ- 
 ment, if he would become truly a Mathematician. 
 
ON THE PROVINCE OB' REASONING. 99 
 
 in all that relates to matters of fact, both kinds of investigation will 
 be united; i.e. some of the facts or principles you reason from as 
 Premises, must he ascertained by observation; or, as in the case of 
 the safety-lamp, the ultimate Conclusion will need confirmation from 
 experience; so that both Physical and Logical Discovery will take 
 place in the course of the same process: we need not, therefore, 
 wonder, that the two are so perpetually confounded. In Mathematics, 
 on the other hand, and in great part of the discussions relating to 
 Ethics and Jurisprudence, there being no room for any Physical 
 Discovery whatever, we have only to make a skilful use of the propo- 
 sitions in our possession, to arrive at every attainable result. 
 
 The investigation, however, of the latter class of subjects differs in 
 other points also from that of the former ; for setting aside the cir- 
 cumstance of our having, in these, no question as to facts, — no room 
 for observation, — there is also a considerable difference in what may 
 be called the process of Logical investigation ; the Premises on which 
 we proceed being of so different a nature in the two cases. 
 
 To take the example of Mathematics, the definitions, which are the 
 principles of our Reasoning, are yerj few, and tlie axioms still fewer; 
 and both are, for the most part, laid down, and 2^l(^^d before the 
 student in the outset; the introduction of a new definition or axiom, 
 being of comparatively rare occurrence, at wide intervals, and with a 
 formal statement ; besides which, there is no room for doubt concern- 
 ing either. On the other hand, in all Reasonings which regard 
 matters of fact, we introduce, almost at evei^y step, fresh and fresli 
 propositions (to a very great number) which had not been elicited in 
 the course of our Reasoning, but are taken for granted ; viz. facts and 
 laws of Nature which are here the principles of our Reasoning, and 
 maxims, or "elements of belief," which answer to the axioms in 
 Mathematics. If, at the opening of a Treatise, for examj)le, un 
 Chemistry, on Agriculture, on Political Economy, &c., the author 
 should make, as in Mathematics, a formal statement of all the propo- 
 sitions he intended to assume, as granted throughout tlie whole work, 
 both he and his readers would be astonished at the number : and, of 
 these, many would be only probable, and there would be much rcjom 
 for doubt as to the degree of probability, and for judgment, in a.sccr- 
 taining that degree. 
 
 Moreover, Mathematical axioms are always employed ])reoisely in 
 the same simjiileform; e.g. the axiom that " things ecjual to the same, 
 are equal to one another," is cited, whenever there is need, in those 
 very words ; whereas the maxims employed in the other class of 
 subjects, admit of, and require, continual modifications in the ap])li- 
 cation of them: e.g. " the stability of the laws of Nature," which is 
 our constant assumption in inquiries relating to Natural Philosophy, 
 assumes many different shapes, and in some of them, does not possess 
 the same absolute certainty as in others: e.g. when from having 
 
100 ox THE PROVINCE OF REASONING. 
 
 always observed a certain sheep ruminating, we infer, that this indivi- 
 dual sheep will continue to ruminate, we assume that " the property 
 which has hitherto belonged to this sheep, will remain unchanged;" 
 when we infer the same property of all sheep, we assume that " the 
 property which belongs to this individual, belongs to the whole 
 species:" if, on comparing sheep with some other kinds of horned 
 animals, and finding that all agree in ruminating, we infer that, " all 
 horned animals ruminate," we assume that *' the whole of a genus 
 or class are likely to agree in any point wherein many species of that 
 genus agree ; " or in other words, " that if one of two properties, &;c., 
 has often been found accompanied by another, and never without it, 
 the former will be ?imvers(2% accompanied by the latter;" now all 
 these are merely different forms of the maxim, that " nature is uniform 
 in her operations;" wiiich, it is evident, varies in exi:»ression in 
 almost every different case where it is applied, and admits of every 
 degree of evidence, from absolute moral certainty, to mere conjecture. 
 
 The same may be said of an infinite number of principles and 
 maxims appropriated to, and employed in each particular branch of 
 study. Hence, all such Reasonings are, in comparison of Mathema- 
 tics, very complex ; requiring so much more than that does, beyond 
 the process of merely deducing the Conclusion Logically, from the 
 Premises ; so that it is no wonder that the longest Mathematical 
 demonstration should be so much more easily constructed and under- 
 stood, than a much shorter train of just Reasoning concerning real 
 facts. The former has been aptly compared to a long and steep, but 
 even and regular, flight of steps, which tries the breath, and the 
 strength, and the perseverance, only ; while the latter resembles a 
 short, but rugged and uneven, ascent up a precipice, which requires 
 a quick eye, agile limbs, and a firm step ; and in which we have to 
 tread now on this side, now on that ; ever considering, as we proceed, 
 whether this projection will afford room for our foot, or whether some 
 loose stone many not slide from under us. 
 
 As for those Ethical and Legal Reasonings which were lately men- 
 tioned, as in some respects resembling those of Mathematics, {viz. 
 such as keep clear of all assertions respecting facts,) they have this 
 difference; that not only men are not so completely agreed respecting 
 the maxims and principles of Ethics and Law, but the meaning also 
 of each term cannot be absolutely, and for ever, fixed by an arbitrary 
 definition; on the contrary, a great part of our labour consists in 
 distinguishing accurately the various senses in which men employ each 
 term, ascertaining which is the most proper, and taking care to avoid 
 confounding them together. 
 
 Of Inference and Proof. 
 
 § 3. Since it appears, from what has been said, that universally a 
 man must possess something else besides the Reasoning faculty, in 
 
ON THE PROVINCE OF REASONING. 101 
 
 order to apply that faculty properly to his own purpose, whatever that 
 purpose may he ; it may he inquired whether some tlieory could not 
 be made out, respecting those " other operatmis,'' and *• intellectual 
 processes distinct from Reasoning, which it is necessary for us some- 
 times to employ in the investigation of truth;"" and whether rules 
 could not be laid down for conducting them. 
 
 Something has, indeed, been done in this way by more than one 
 writer ; and more might probably be accomplished by one who should 
 fully comprehend, and carefully bear in mind the principles of Logic, 
 properly so called ; but it would hardly be possible to l>uild up any 
 thing like a regular Science, respecting these matters, such as Logic 
 is, with respect to the theory of Reasoning. It may he useful, how- 
 ever, to observe, that these '* other operations" of which we have been 
 speaking, and which are preparatory to the exercise of Reasoning, are 
 of two kinds, according to the nature of the end proposed ; for Reason- 
 ing comprehends Inferring and Proving ; whicli are not two different 
 things, but the same thing regarded in two different p)oinis of view : 
 (like the road from London to York, and the road from York to 
 London,) he who infers,*' proves; and he who proves, infers; but the 
 word '* infer" fixes the mind f^'st on the Premiss, and then on the 
 Conclusion ; the word " prove," on the contrary, leads the m'md from 
 the Conclusion to the Premiss. Hence, the substantives derived 
 from these Avords respectively, are often used to express that which, 
 on each occasion, is last in the mind ; Inference being often used to 
 signify the Conclusion, {i.e. Projposition inferred) and Proof, the 
 Premiss. We say also *' How do you jjrove that ?" and " What do 
 you infer from that ?" which sentences would not be so properly 
 expressed if we were to transpose those verbs. One might, therefore, 
 define Proving, " the assigning of a reason or argument fur the sup- 
 port of a given proposition;" and "Inferring,'' the " deduction of a 
 Conclusion from given Premises." In the one case our Conclusion is 
 given, {i.e. set before us) and we have to seek for arguments ; in the 
 other, our Premises are given, and we have to seek for a Conclusion ; 
 i.e. to put together our own propositions, and try 2i:hal will follow 
 from them ; or, to speak more Logically, in the one case, we seek to 
 refer the subject of which we would predicate something, to a class to 
 which that predicate will (affirmatively or negatively) ap])ly ; in the 
 other we seek to find comprehended, in the subject of which we have 
 predicated something, some other term to whicli that predicate had 
 not been before applied. Each of these is a definition of Reasoning. 
 
 To infer, then, is the business of tlie Philosojiher ; to jrrorc, of tlie 
 Advocate ; the former, from the great mass of known and admitted 
 truths, wishes to elicit any valuable additional truth whatever, tliat 
 has been hitherto unperceived ; and, perhaps, without knowing with 
 
 * D. Stewart. ^ , 
 
 6 We mean, of course, when tlic word is understood to ini|>ly cvrnrt Infereiu-c. 
 
102 ON THE PROVINCE OF REASONING. 
 
 certainty, what will he the terms of his Conclusion. Thus the 
 Mathematician, e.g. seeks to ascertain what is the ratio of circles to 
 each other, or ivhat is the line whose square will be equal to a given 
 circle : the Advocate, on the other hand, has a proposition put before 
 him, which he is to maintain as well as he can ; his business, there- 
 fore, is to JiTid middle terms, (which is the inventio of Cicero ;) the 
 Philosopher's, to combine and select known facts, or principles, 
 suitably for gaining from them conclusions which, though implied in 
 the Premises, were before unperceived ; in other words, for making 
 *' Logical Discoveries." Such are the respective preparatory processes 
 in these two branches of study. They are widely different ; — they 
 arise from, and generate, very different habits of mind ; and require 
 a very different kind of training and precept. The Lawyer, or Contro- 
 versialist, or, in short, the Rhetorician m general, who is, in his own 
 province, the most skilfid, may be but ill-fitted for Philosophical 
 investigation, even where there is no observation wanted, — when the 
 facts are all ready ascertained for him. And again, the ablest Philo- 
 sopher may make an indifferent disputant ; especially, since the 
 arguments which have \edhim to the Conclusion, and have, with him, 
 the most weight, may not, perhaps, be the most powerful in contro- 
 versy. The commonest fault, however, by far, is to forget the 
 Philosopher or Theologian, and to assume the Advocate, improperly. 
 It is therefore of great use to dwell on the distinction between these 
 two branches : as for the bare process of Reasoning, that is the same 
 in both cases ; but the preparatory processes which are requisite in 
 order to employ Reasoning profitably, these we see branch off into 
 two distinct channels. In each of these undoubtedly, useful rules 
 may be laid down ; but they should not be confounded together. 
 Bacon has chosen the department of Philosophy, giving rules in his 
 Organon, (not only for the conduct of experiments to ascertain new 
 facts, but also for the selection and combination of known facts and 
 principles,) with a view of obtaining valuable Inferences^; and it is 
 probable that a system of such rules is what some writers mean (if 
 they have any distinct meaning) by their proposed " Logic." In the 
 other department, precepts have been given by Aristotle and other 
 Rhetorical writers, as a part of their plan. How far these precepts 
 are to be considered as belonging to the present system, — whether 
 *' method" is to be regarded as a joari of Logic, — whether the matter 
 of Logic is to be included in the system, — whether Bacon's is properly 
 to be reckoned a kind of Logic ; all these are merely verbal questions 
 relating to the extension, not of the Science, but of the name. The 
 bare process of Reasoning, i.e. deducing a Conclusion from Premises, 
 must ever remain a distinct operation from the assumption of Premises, 
 however useful the rules may be that have been given, or may be 
 given, for conducting this latter process, and others connected with 
 it; and however properly such rules may be subjoined to the precepts 
 
ON THE PROVINCE OF REASONING. 103 
 
 of that system to which the name of Logic is applied in the narrowest 
 sense. Such rules as we now allude to may be of eminent service ; 
 but they must always be, as we have before observed, comparatively 
 vague and general, and incapable of being built up into a regular 
 demonstrative theory like that of the Syllogism ; to which theory they 
 bear much the same relation as the principles and rules of Poetical 
 and Rhetorical criticism, to those of Grammar ; or those of practical 
 Mechanics, to strict Geometry. We find no fault with the extension of 
 a term ; but we would suggest a caution against confounding together, 
 by means of a common name, things essentially different : and above 
 all, we deprecate the sophistry of striving to depreciate what is called 
 *' the School Logic," by perpetually contrastiiuj it with systems with 
 which it has nothing in common but the name ; and whose object is 
 essentially different. 
 
 It is not a little remarkable that writers whose expressions tend to 
 confound together, by means of a common name, two branches of 
 study which have nothing else in common, (as if they were two dif- 
 ferent plans for attaining one and the same object,) have themselves 
 complained of one of the effects of this confusion, viz. the introduction, 
 early in the career of Academical Education, of a course of Zo^/c ; 
 under which name, they observe, *' men now universally comprehend 
 the works of Locke, Bacon, <fec." which, as is justly remarked, are 
 unfit for beginners. Now this would not have happened, if men had 
 always kept in mind the meaning or meanings of each name they 
 used. And it may be added, that, however justly the word Logic 
 may be thus extended, we have no ground for applying to the 
 Aristotelian Logic the remarks above quoted respecting the Baconian ; 
 which the ambiguity of the word, if not carefully kept in view, might 
 lead us to do. Grant that Bacon's work is a part of Logic ; it no 
 more follows from the unfitness of that for learners, that the elements 
 of the theory of Reasoning should be withheld from them, than it 
 follows that the elements of Euclid, and common Arithmetic, are untit 
 for boys, because Newton s Prhmpia, which also bears the title (tf 
 Mathematical, is above their grasp. Of two branches of study which 
 bear the same name, or even of two parts of the same branch, the one 
 may be suitable to the commencement, the other to the close, of 
 the Academical career. 
 
 At whatever period of that career it may be proper to introduce 
 the study of such as arc usually called Metaphysical writers, it may 
 be safely asserted, that those who have had the most experience in 
 the business of giving instruction in Logic, j)ropcrly so called, togetlier 
 with other branches of knowledge, prefer and generally pursue the 
 plan of letting their pupils enter on that study next in order, after 
 the elements of Mathematics. 
 
104 ON THE PROVINCE OF REASONING. 
 
 Of Verbal and Real Questions. 
 
 § 4. The ingenious author of the Philosophy of Rhetoric having 
 maintained, or rather assumed, that Logic is applicable to Verbal 
 controversy alone, there may be an advantage, though it has been 
 our aim throughout to show the application of it to all Reasoning, in 
 pointing out the difference between Verbal and Real Questions, and 
 the probable origin of Campbell's mistake ; for to trace any error to 
 its source, will often throw more light on the subject in hand than 
 can be obtained if we rest satisfied with merely detecting and refut- 
 ing it. 
 
 Every Question that can arise, is in fact a Question whether a 
 certain Predicate is or is not appHcable to a certain subject ; and 
 whatever other account may be given by any writer of the nature of 
 any matter of doubt or debate, will be found, ultimately, to resolve 
 itself into this. But sometimes the Question turns on the meaning 
 and extent of the terms employed ; sometimes on the things signified 
 by them. If it be made to appear therefore, that the opposite sides 
 of a certain Question may be held by persons not differing in their 
 opinion of the matter in hand, then that Question may be pronounced 
 Verbal, as depending on the different senses in which they respectively 
 employ the terms. If on the contrary it appears that they employ 
 the terms in the same sense, but still differ as to the application of 
 one of them to the other, then it may be pronounced that the Question 
 is Real, — that they differ as to the opinions they hold of the things in 
 Question. 
 
 If, for instance, two persons contend whether Augustus deserved 
 to be called a great man, then if it appeared that the one included 
 under the term " great," disinterested ^9a^?'zo^2sm, and on that ground 
 excluded Augustus from the class, as wanting in that quality, and 
 that the other also gave him no credit for that quality, but understood 
 no more by the term " great," than high intellectual qualities, energy 
 of character, and brilliant actions, it would follow that the parties did 
 not differ in opinion except as to the use of a term, and that the 
 Question was Verbal. If again it appeared that the one did give 
 Augustus credit for such patriotism as the other denied him, both of 
 them including that idea in the term great, then the Question would 
 be Real. Either kind of Question, it is plain, is to be argued accord- 
 ing to Logical principles ; but the middle terms employed would be 
 different ; and for this reason among others it is important to dis- 
 tinguish Verbal from Real controversy. In the former case, e.g. it 
 might be urged with truth, that the common use of the expression 
 *' great and good" proves that the idea of good is not implied in the 
 ordinary sense of the word great ; an argument which could have, of 
 course, no place in deciding the other Question. 
 
 It is by no means to be supposed that all Verbal Questions are 
 
ON THE PROVINCE OF REASONING. 105 
 
 trifling and frivolous ; it is often of the highest importance to settle 
 correctly the meaning of a word, either according to ordinary use, or 
 according to the meaning of any particular writer, or class of men ; 
 but when Verbal Questions are mistaken for Real, much confusion of 
 thought and unprofitable wrangling will bo generally the result. Nor 
 is it always so easy and simple a task, as might at first sight appear, 
 to distinguish them from each other : for several objects to which one 
 common name is applied will often have many points of difference, 
 and yet that name may perhaps be applied to them all in the same 
 sense, and may be fairly regarded as the genus they come under, if 
 it appear that they all agree in what is designated by that name, and 
 that the differences between them are in points not essential to the 
 character of the genus. A cow and a horse differ in many respects, 
 but agree in all that is implied by the term " quadruped," which is 
 therefore applicable to both in the same sense. So also the houses 
 of the ancients differed in many respects from ours, and their ships 
 still more; yet no one would contend that the terms "house" and 
 "ship," as applied to both, were ambiguous, or that oIko; might not 
 fairly be rendered house, and vxv;, shij) : because the essential charac- 
 teristic of a house is, not its being of this or that form or materials, 
 but its being a dwelling for men ; these therefore would be called two 
 different kinds of houses ; and consequently the term " house" would 
 be applied to each, without any equivocation, in the same sense : and 
 so in the other instances. On the other hand, two or more things 
 may bear the same name, and may also have a resemblance in many 
 points, and may from that resemblance have come to bear the same 
 name, and yet if the circumstance which is essential to each be want- 
 ing in the other, the term may be pronounced ambiguous : e.g. the 
 word "Priest" is applied to the ministers of the Jewish and of the Pagan 
 rehgions, and also to those of the Christian : and doubtless the term 
 is so used in consequence of their being both ministers, (in some sort) 
 of religion. Nor would every difference that might be found between 
 the Priests of different religions constitute the term ambiguous, pro- 
 vided such differences were non-essential to the idea suggested by the 
 word Priest ; as e.g. the Jewish Priest served the true God, and the 
 Pagan, false Gods : this is a most important difierencc, but does not 
 constitute the term ambiguous, because neither of these circumstances 
 is implied and suggested by the term ' Uoivg, which accordingly was 
 applied both to Jewish and Pagan Priests, l^ut the term 'Lert',' does 
 seem to have implied the ofiice of offering sacnnjice, atoning for the 
 sins of the people, and acting as mediator between man and the 
 object of his worship ; and accordingly that term is never applied to 
 any one under the Christian system, except to the one great Mediator. 
 The Christian ministers not having that office which was implied as 
 essential in the term 'li^ii/g, were never called by that name, but by 
 that of TTgea/SyTtgof. It may be concluded, therefore, that the term 
 
106 ON THE PROVINCE OF REASONING. 
 
 Priest is ambiguous, as corresponding to the terms ' Is^gyj and 'jr^ia(iv- 
 n^og respectively, notwithstanding that there are points in which these 
 two agree. These therefore should be reckoned, not two different 
 kinds of Priests, but Priests in two different senses ; since, (to adopt 
 the phraseology of Aristotle,) the definition of them so far forth as 
 they are Priests, would be different. 
 
 It is evidently of much importance to keep in mind the above dis- 
 tinctions, in order to avoid, on the one hand, stigmatizing as Verbal 
 controversies, what m reality are not such, merely because the 
 Question turns on the applicabihty of a certain Predicate to a certain 
 subject ; or on the other hand, falling into the opposite error of mis- 
 taking words for things, and judging of men's agreement or disagree- 
 ment in opinion in every case, merely from their agreement or dis- 
 agreement in the terms employed. 
 
 Of Realism. 
 
 § 5. Nothing has a greater tendency to lead to the mistake just 
 noticed, and thus to produce undetected Verbal Questions and fruitless 
 Logomachy, than the prevalence of the notion of the Realists, that 
 genus and species were some real Things, existing independently of 
 our conceptions and expressions, and that, as in the case of singular 
 terms, there is some real individual corresponding to each, so in 
 common terms also there is something corresponding to each, which 
 is the object of our thoughts when we employ any such term.^ Few, 
 if any, indeed, in the present day avow and maintam this doctrine ; 
 but those who are not especially on their guard, are perpetually sliding 
 into it unawares. Nothing so much conduces to this as the trans- 
 ferred and secondary use of the words " same," " one and the same," 
 " identical, &;c." when it is not clearly perceived and carefully borne 
 in mind that they are employed in a secondary sense, and that more 
 frequently even than in the primary. Suppose e.g. a thousand 
 persons are thinking of the sun, it is evident it is one and the same 
 individual object on which all these minds are employed ; so far all is 
 clear : but suppose all these persons are thinking of a triangle ; not 
 any individual triangle, but triangle in general ; and considering per- 
 haps the equality of its angles to two right angles ; it would seem as 
 if in this case also, their minds were all employed on " one and the 
 same" object: and this object of their thoughts, it may be said, 
 cannot be the mere word triangle, but that which is meant by it ; nor 
 again, can it be every thing that the word vrill apply to, for they are not 
 thinking of triangles, but of one thing : those who do not acknowledge 
 that this " one thing" has an existence independent of the human 
 mind, are in general content to tell us by way of explanation, that the 
 object of their thoughts is the abstract "idea" of a triangle; an 
 
 7 A doctrine commonly, but falsely, attributed to Aristotle, who expressly contra- 
 dicts it. Categories, trip) olvUf. 
 
ON THE PROVINCE OP REASONING. 107 
 
 explanation which satisfies, or at least silences many, though it may 
 be doubted whether they very clearly understand what sort of a thini^ 
 an idea is, which may thus exist in a thousand dittercni luinds at once,"' 
 and yet be " one and the same." 
 
 The fact is, that " unity" and *' sameness" arc in such cases 
 employed, not in the primary sense, but to denote perfect similarity. 
 When we say that ten thousand different persons have all " one and 
 the same" idea in their minds, or are all of "one and the same" opinion, 
 we mean no more than that they are all thinking eccadly alike; when 
 we say that they are all in the ** same" posture, we mean that they 
 are all placed alike: and so also they are said all to have the 
 ** same" disease when they are all diseased alike. 
 
 The origin of this secondary sense of the words, " same," '* one," 
 "identical," &c. (an attention to which would clear away an incal- 
 culable mass of confused Reasoning and Logomachy,) is easily to be 
 traced to the use of language and of other signs, for the purpose of 
 mutual communication. If any one utters the " one single" word 
 *' triangle," and gives " one single" definition of it, each person who 
 hears him forms a certain notion in his own mind, not differing in any 
 respect from that of each of the rest ; they are said therefore to have 
 all " one and the same" notion, because, resulting from, and corre- 
 sponding with, that which is in the primary sense " one and the 
 same" expression; and there is said to be " one single" idea of every 
 triangle, (considered merely as a triangle,) because one single name 
 or definition is equally applicable to each. In like manner all the 
 coins struck by the same single die, are said to have "one and the 
 same" impression, merely because the one description which suits one 
 of these coins will equally suit any other that is exactly like it. 
 
 It is not intended to recommend the disuse of the words " same," 
 *' identical," &lc. in this transferred sense ; which, if it were desirable, 
 would be utterly impracticable ; but merely, a steady attention to the 
 ambiguity thus introduced, and watchfulness against the errors thence 
 arising. The ditficulties and perplexities which liave involved the 
 questions respecting personal identity, among others, may be traced 
 principally to the neglect of this caution. But tlic further considera- 
 tion of that question would be unsuitable to the subject of this article. 
 
INDEX.* 
 
 Abbreviations, 53. 
 
 Abstraction, 14, 20, 25. 
 
 Abstractions, Arbitrary, 21. 
 
 Abstract Principles, difficulty of per- 
 ceiving the ultimate use of, 7. 
 
 Abstract Terms, 24. 
 
 Accident, 26, 27. 
 
 Accidental Definition, 30. 
 
 Affirmative Categorical Propositions, 
 32, 33. 
 
 Affirmative Conclusions, 38. 
 
 Ambiguity, remedy for, 72. 
 
 Ambiguous Middle, 66. 
 
 Ambiguous Words, 63, 70, 81. 
 
 Analogous Terms, 64. 
 
 Analytical and Synthetical modes of 
 procedure, 7. 
 
 Analytical Sketch of the Logical sys- 
 tem, 8. 
 
 Antecedent, 47, 51. 
 
 Anti-Reformers, Fallacy of, 82. 
 
 Antisthenes, 2. 
 
 Apprehension (simple), 23. 
 
 A priori Reasoning, 53. 
 
 Arbitrary Abstractions, 21. 
 
 Archytus, 3. 
 
 Aristotle, His dictum de omni ct nullo, 
 13, 37. 
 
 , the founder of Logic, 3. 
 
 Aristotelian Logic, 103. 
 
 Arguing in a Circle, 61, 76. 
 
 Argumentation, 77. 
 
 Argument, 10, 23, 37. 
 
 Fallacious or Apparent, 
 
 15, 66. 
 
 test of its validity, 11. 
 
 Arguuientum ad hominem, 80. 
 
 ad verecundiam, 80. 
 
 ad populum, 80. 
 
 ad rem, 80. 
 
 ad ignorantiam, 80. 
 
 Assertion, 32. 
 
 Assumption of Premises in Induction, 
 87. 
 
 Bacon, 4. 
 
 , his censure of Logic. 4. 
 
 Baconian Logic, 103. 
 
 Barbara, 41. 
 
 Baroko, 41. 
 
 Begging the Question. 61. 7.'). 
 
 Bokardo, 41. 
 
 Bramantip, 41. 
 
 Camenes, 41. 
 Camestres, 41. 
 
 Campbell's Misapprehension of Aris- 
 totle's dictum, 13. 
 Categorical Propositions, 32, 46. 
 Categories, 90. 
 Causal Conjunction, 10. 37. 
 Cause and Reason dift'ereut, 77. 
 Celarent, 41. 
 Cesare, 41. 
 
 Classifications for special objects, 21. 
 Common Terms, 19, 25, 27. 
 Composition, Fallacy of, 73. 
 Comprehensiveness of Terms, 89. 
 Conclusion, 37, 38. 
 Conditional Propositions, 48. 
 Conditionals, 47. 
 Conjunction, Causal, 10, 37 
 Conjunction, Illative, 10, 37. 
 Consequent, 47, 51. 
 Constructive Conditional Syllogism, 48. 
 Contingent matter of a Proposition, 33. 
 Contradictory Propositions, 34. 
 Contraposition, Conversion by, 36. 
 Contrary Propositions, 34. 
 Controversialist, 102. 
 Converse, 35. 
 i Conversion, 35. 
 
 , Illative, 35. 
 
 , Sini])lc. 35 
 
 Conversion by contra-position. 36. 
 
 by limitation, 36. 
 
 by negation, 36. 
 
 of a IVoposition, 35. 
 
 per accidens, 36. 
 
 * The author of the Treatise on Logic is not accountable for the content* of 
 this Index. — Editor Ency. Mki. 
 
110 
 
 INDEX. 
 
 Convertible Tenns, 36. 
 Copula, 24, 46. 
 Cross Divisions, 29. 
 
 Darapti, 41. 
 Darii, 41. 
 
 Datisi, 41. 
 Definition, 29. 
 
 , Nominal and Real, 96. 
 
 , Rules for, 31, 
 
 Description, 30. 
 
 Destructive Conditional Syllogism, 48, 
 
 Detection of Fallacies often difficult, 64. 
 
 , necessity of, 63. 
 
 Dictum (Aristotle's) "c?e omni et nullo" 
 
 13, 37. 
 Difference (Differentia) 26, 27. 
 Dilemma, 49. 
 
 Complex Constructive, 49. 
 
 Destructive, 50. 
 
 Improper, 50. 
 
 Simple Constructive, 49. 
 
 True, 50. 
 
 Dimaris, 41. 
 Disamis, 41. 
 Discourse, 23, 37. 
 Discovery of Truth, 88, 90. 
 Disjunctive Propositions, 49. 
 Distributed Term defined, 16. 
 Distribution of Terms, 16, 34. 
 Division, Fallacy of, 73. 
 Division, Logical, 28. 
 Division of Terms, 89. 
 
 Elliptical Expressions, 64. 
 EnthjTneme, an Argument in which one 
 of the Premises is suppressed, 10, 52. 
 Equivalents, 53. 
 Equivocal Words, 70- 
 Equivocation, Fallacy of, 67. 
 Essential Definition. 30. 
 Ethical Propositions, 91. 
 Euclid of Megara, 2. 
 Evidence, 87, 93. 
 Example, 88. 
 Exposita, 35. 
 Extremes, 24. 
 
 Fallacia a dicto secundum quid ad 
 
 dictum simpliciter, 75. 
 Fallacia Accidentis, 74. 
 Equivocationis, 70. 
 
 Figurae Dictionis, 67. 
 
 Plurium Interrogationum. 69. 
 
 Fallacies, division of, 57. 
 
 — extra dictionem, 57. 
 
 Fallacies indictione, 57. 
 
 in Form, 65. 
 
 , Logical, 59. 
 
 , Non-Logical 60,75. 
 
 , Material, 60, 75. 
 
 , Scheme of, 62. 
 
 , Semi-logical, 59. 67. 
 
 Fallacy defined, 56. 
 
 Fallacy of Anti-Reformers, 82. 
 
 Composition, 73. 
 
 Division, 73. 
 
 Equivocation, 67, 70. 
 
 Interrogation, 69. 
 
 Infidels, 82. 
 
 Irrelevant Conclusions, 78. 
 
 Jests, 83. 
 
 Objections, 82. 
 
 Proving a part only, 82. 
 
 False Proposition, 34. 
 
 Falsity, 60, 76. 
 
 Familiar Terms often misapplied, 60. 
 
 Felapo, 41. 
 
 Felapton, 41. 
 
 Ferio, 41. 
 
 Feriso, 41. 
 
 Festino, 41. 
 
 Figure of a Syllogism, 40. 
 
 First Intention of a Term, 70. 
 
 Form, Fallacies in, 65. 
 
 Fresison, 41. 
 
 Galen, 4. 
 
 Generalization, 14, 20, 25, 89. 
 
 Genus, 26. 
 
 History of Logic, 1. 
 
 Hypothetical Propositions, 32, 46, 47. 
 
 Hypotheticals, 46. 
 
 . — — , Reduction of, 51. 
 
 Identical, ambiguity of, 106. 
 
 Ignoratio-elenchi, 60, 78. 
 
 Illative Conjunction, 10, 37. 
 
 Illative Conversion, 35. 
 
 Impossible Matter of a Proposition, 33. 
 
 Incompatibles, 74. 
 
 Indefinite Propositions, 17, 33. 
 
 Indirect Reduction, 45. 
 
 Individual, 28. 
 
 Induction, 85. 
 
 Inductive Arguments, 53, 85. 
 
 Inductive Process, 87. 
 
 Inference, 37, 100, 101. 
 
 Inferring, 101. 
 
 Infidel Arguments on Miracles, 74. 
 
 Infidels, Universal Fallacy of, 82. 
 
INDEX. 
 
 Ill 
 
 Infima Species, 27. 
 Information, 90. 
 Inquiry, process of, 86. 
 Inseparable Accidents, 27. 
 Instruction, 90, 92. 
 Interrogation, Fallacy of, 69. 
 Investigation, 77, 87. 
 Irrelevant Conclusion, Fallacy of, 78. 
 
 Jests are Fallacies, 83. 
 Judgment, 23. 
 
 Language, 23. 
 
 Limitation, Conversion by, 36. 
 
 Locke, 4. 
 
 Logic, a method of unfolding and ana- 
 lysing all reason, not a peculiar 
 method of reasoning, 9. 
 
 Logic defined, 1, 24. 
 
 Logical Definition, 30. 
 
 Division, 28. 
 
 Fallacies, 59. 
 
 Reasoning, 12. 
 
 Logomachy, 105, 107. 
 
 Major Term of a Syllogism, 38. 
 
 Material Fallacies, 60, 75. 
 
 Mathematical Discoveries, 98. 
 
 Propositions, 91, 95. 
 
 Reasoning, 99. 
 
 Matter of a Proposition, 33, 34. 
 
 Matters of Fact, 90, 93. 
 
 Metaphor, 71. 
 
 Middle Term, Non-distribution of, 16. 
 
 Distribution of, 18. 
 
 of a Categorical Syllo- 
 gism, 16, 38. 
 
 Minor Term of a Categorical Syllogism, 
 38. 
 
 Mistaken views of many objectors to 
 Logic, 5. 
 
 Modal Categorical Propositions, 32, 46. 
 
 Modals, 46. 
 
 Modal Syllogisms, 46. 
 
 Mood of a Categorical Syllogism, 40. 
 
 Narrowness of mind, 21. 
 Necessary Matter of a Proposition, 33. 
 Negation, Conversion by, 36. 
 Negative Categorical Propositions, 32, 
 
 33. 
 Negative Conclusions, 38. 
 New Truths, 88, 90. 
 Nominal Definition, 29, 96. 
 Non-Distribution of the Middle Term, 
 
 16. 
 
 Non-Logical Fallacies, 60, 75. 
 
 Objections, Fallacy of, 82. 
 Observation, 90. 
 Operations of the Mind, 23. 
 Opposition of Terms, 34. 
 Ostensive Reduction of Syllogisms, 43. 
 
 Paronymous words, 67. 
 
 Particular Propositions, 17, 33. 
 
 Petitio principii, 61, 75. 
 
 Physical Definition, 30. 
 
 Physical Discoveries, 93, 94. 
 
 Per accidens, Conversion, 36. 
 
 Plato's Theory of Ideas, 91. 
 
 Porphyry, 4 
 
 Predicables, 26, 27. 
 
 Predicaments, 90. 
 
 Predicate, 17, 24, 51. 
 
 Predication, 19. 
 
 Premiss, Premises, 10, 37. 
 
 Proof, 100. 
 
 Property, 26, 27. 
 
 Propositions, 10, 17, 23, 32. 
 
 Propositions that Distribute the Predi- 
 cate, 34. 
 
 Propositions that Distribute the Sub- 
 ject, 34. 
 
 Proving, 101. 
 
 Proximum Genus, 27. 
 
 Pure Categorical Propositions, 32. 
 
 , proof of their vaUdity, 38. 
 
 Quality of a Proposition, 17. 
 
 Quality of our Reasoning, on whai it 
 
 depends, 22. 
 Quantity of a Proposition, 17. 
 Question, 37. 
 Questions, verbal and real. 104. 
 
 Real Definitions, 29, 96. 
 
 Realism, lOG. 
 
 Real Questions, 104. 
 
 Reasoning, ambiguous use of the word, 
 
 96. 
 , an oi)cration of the luimi, 
 
 23, 37. 
 , desirableness of gcntral 
 
 Rules for, 9. 
 
 from Induction. y3. 
 
 , Province of, 85 
 
 , the process of, ilie sann.- iu 
 
 all cases, 8. 
 -, universal principle of, 12. 
 
 Reason, Term applied to a Troiniss 
 placed after its Conclusion, 10, 37. 
 
112 INDEX. 
 
 Reductio ad Impossibile, 44. 
 Reduction of Hypotheticals, 51. 
 Reduction of Syllogisms, 43. 
 Remote Genus, 27. 
 
 Same, ambiguity of the word, 106. 
 
 Schoolmen, Logic of the, 4. 
 
 Scientific Truths, 95. 
 
 Second Intention of a Term, 70. 
 
 Sentence Indicative, 32. 
 
 Separable Accidents, 27. 
 
 Shifting Ground during an Argument, 
 
 Fallacy of, 81. 
 Signs, see Symbols. 
 Signs, Universal and Particular, 33. 
 Simple conversion, 35. 
 Singular Propositions, 33. 
 Singular Terms, 25. 
 Sorites, 52. 
 Species, 26. 
 Stewart, Professor Dugald,his objections 
 
 to Aristotle's dictum unfounded, 13. 
 Subaltern Species and Genus, 26. 
 Subcontrary Opposition, 34. 
 Subject of a Proposition, 51. 
 Summum Genus, 27. 
 Syllogisms, Defined, 37. 
 
 , Explained, 10, 23. 
 
 , Figures of, 40. 
 
 , Hypothetical, 47. 
 
 Syllogisms, Moods of, 40. 
 
 , Pure Categorical, 38. 
 
 , Reduction of, 43. 
 
 , Rules for proving their 
 
 Validity, 38. 
 Symbols explained : — 
 
 A, E, I, O, 33. 
 n, i, c, f, V, 34. 
 
 B, C, D, F, 45. 
 m, s, ss, p, k, 45. 
 
 Technical meanings of words, 70. 
 Terms, 23. 
 
 , Distributed, 16, 24, 34. 
 
 , Undistributed, 16, 24, 34. 
 
 Testimony, 90. 
 True Proposition, 34. 
 Truth, Discovery of, 88. 
 Truths, New, 88, 90. 
 
 Undistributed Terms defined, 1 6. 
 Universal Propositions, 1 7, 33. 
 
 Verbal Controversy, 72. 
 Verbal Questions, 104. 
 
 Watts's Right Use of Reason, 5. 
 Weak Arguments detrimental, 66. 
 
 Zeno, the earliest wTiter on Logic, 2. 
 
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 and corks. A, contains pure zinc and pure muriatic acid, not stronger than 100° 
 (= sp. gr. 1"031). B, contains a solution of caustic potash; C, a solution of acetate 
 of lead ; D, a solution of nitrate of silver. When it is proved that hydrogen gas 
 passes through the V-tubes without action, the arsenical liquor is poured into the bottle 
 A, by the funnel h. The great size of this bottle permits the frothing to occur with- 
 out damage. The arseniuretted hydrogen gas passes through the receivers. In B it 
 deposits sulphuretted hydrogen, and other impurities. In C it produces no action, 
 if the washing in Bis sufficient; that is, if the muriatic acid is not too strong, so as 
 to force the operation too rapidly. In D it throws down metallic silver, and the 
 arsenic remains in solution. When the current of gas ceases, the liquor in D is 
 mixed with muriatic acid to throw down the excess of silver, and the liquor is 
 filtered and evaporated to dryness. The product is pure arsenic acid, which can be 
 submitted to its appropriate tests. 
 
 For other Uses of this Apparatus, see Chemical Recreations, p. 543. 
 
 1730. BOTANY.— A MANUAL of BOTANY ; being an Introduction to the 
 Study of the Structure, Physiology, and Classification of Plants, By 
 John Hutton Balfour, M.D., F.L.S., F.R.S.E., Professor of Medicine 
 and Botany in the University of Edinburgh. One thick Volume crown 
 octavo, 664 pages, illustrated by 831 Engravings on Wood. Price 12s. 6c?., 
 cloth lettered. 
 
1849,] 
 
 GRIFFIN'S SCIENTIFIC CIRCULAR. 
 
 1731. BEAKED TUMBLERS for 
 PRECIPITATIONS. Fig. 
 
 1731. Nest of six sizes, con- 
 tents 2 to 24 ounces of water ; 
 best hard white Bohemian glass, 
 uniform throughout, without 
 punty-mark, and with spout, 
 per nest, 5s. 
 
 These glasses are peculiarly adapted 
 for the operations of Mineral analyses. 
 They are of convenient sizes for the 
 solutions, are all wide and short enough 
 to permit the fingers to reach the bottom 
 
 V 
 
 17;n. 
 
 17:?2. 
 
 within, so that the precipitates can be effectually removed without loss, and tlio 
 vessels be readily cleaned. 
 
 BEAKER GLASSES (Berzelius's ) for HOT LIQUORS, Firj.rr^i, 
 with projecting edge, equally thin at the bottom and sides, of the best 
 hard white Bohemian glass, without punty-mark at the bottom, and 
 smooth on the edge. 
 
 t. d. 
 
 3 ounces of water 1 6 
 
 G ounces of water i' H 
 
 28 ounces of water 4 
 
 2 to 100 ounces of water 7 6 
 
 2 to 180 ounces of water 10 (J 
 
 
 
 In Aests, at 
 
 the following prices .- — 
 
 1732. 
 
 Nest of 
 
 3 small sizes . . 
 
 . Contents, 1 to 
 
 1733. 
 
 jj 
 
 5 small sizes . . 
 
 . „ 1 to 
 
 1734. 
 
 }) 
 
 4 large sizes . . 
 
 „ 5 to 
 
 1735. 
 
 jj 
 
 8 large sizes . . 
 
 „ 2 to ] 
 
 1736. 
 
 )> 
 
 12 large sizes 
 
 . „ 2 to ] 
 
 CONCHOLOGY.— COLLECTIONS of SEA, FRESH-WATER, a.nd 
 LAND SHELLS, systematically arranged and accurately named, in 
 accordance with the most esteemed Naturalists. 
 
 1737. One hundred Specimens, 1/. 11^. Gd. 
 
 1738. Four hundred Specimens, 8/. 8.?, 
 
 1739. Five hundred Specimens, 12/. 12s. 
 
 1740. CHEMICAL RECREATIONS: A Popular Compendium of Exp.n- 
 
 mental Chemistiy, for the Use of Beginners. By Joii.n Jhsftii Guikkin. 
 F.C.S. The Ninth Edition, entirely rewritten, and Illustrated by 
 Four Hundred Figures of Apparatus. InOne Volume, 18mo, of 576 pagos, 
 price 7^. 6d., bound in embossed roan. 
 
 This work is ofTored as a Manual of Experimental Chemistry for the u<se of 
 beginners. Students of Chemistry, Sehoohuasters wlio desiri' to teach the KU-ni< nta 
 of Chemistry, and j)ersons engaged in riuumaey, Calico-printing, or other Cheinii.il 
 Arts, will find useful information in its pages. Tlie subji-ets investigati <l an* »ueh 
 as urgently demand the notice of beginners ; and the author has endiuvouritl to 
 elucidate tliem etiectively. The ex]>eriini nts ifiven are striking and ronvineing, 
 and such as can be performed with facility and economy. The precaution* neci»- 
 sary to ensure success and safety are fully detailed, and, as far us p<>vsil)lo, the 
 experiments are cjhihittd by means of four hundred tiguresof uppanitu!^. many of 
 which represent new and simplified instruments, sj)ecially intended to aid tlu' 
 researches of young Chemists. To render the work i)nictically us«-ful ^> (h.^c 
 en(/arjed in choniCal occupations, the author has inchufed full instrurtit>n» for the 
 analysis of acids, alcalies, salts, and other substances used ext.nsivi-ly in the Art-. 
 
GRIFFIN'S SCIENTIFIC CIRCULAR. 
 
 [May, 
 
 GRIFFIN'S PORTABLE CHEMICAL LABORATORIES. 
 
 In compliance with the request of many of our friends, we are now preparing a 
 Series of PORTABLE CABINETS of Chemical Apparatus and Prepara- 
 tions, adapted for the performance of the Experiments described in the above 
 work. They will be more or less complete according to the price, but the very 
 smallest will contain materials sufficient for an extensive series of instructive expe- 
 riments. They will not be toys, containing merely the articles adapted for half-a- 
 dozen showy experiments that lead to no results ; but they will be so furnished 
 that the student who uses the articles according to the instructions given in the 
 book will acquire considerable experience in chemical researches. 
 
 1741. No. 1 contains 24 boxes and 8 bottles, with Chemical Preparations, and 
 
 nearly 40 pieces of Apparatus, in a mahogany box, I6s. 
 
 1742. No. 2 contains 30 boxes and 8 bottles, with Chemical Reagents, and 
 
 nearly 60 pieces of Apparatus, in a mahogany box, with lock and key, 
 1^. Us. 6d. 
 
 1743. No. 3 contains 30 bottles, with Chemical Preparations, and about 80 pieces 
 
 of Apparatus, including a lamp-furnace, in a deal box, with lock and 
 key, 2/. 25. 
 
 1744. No. 4 contains a superior assortment of small-sized Apparatus, with 
 
 Chemical Tests, in boxes, and Stoppered Bottles for Solutions, in a 
 mahogany box, with lock and key, 21. 12s. 6d. 
 
 1745. No. 5, the preceding Collection, with some useful additions, in a French 
 
 polished mahogany box, with lock and key, 31. 3s. 
 
 Various larger collections of Apparatus are always on view at our Chemical 
 Museums in London and Glasgow. 
 
 1746. CHEMICAL TESTS, ALL ABSOLUTELY PURE, at greatly Reduced 
 Prices. Weight, Imperial Avoirdupois, 1 lb. = 16 oz. = 7000 grains. 
 Chemical Preparations of good commercial quality, and those substances 
 useful in experimenting, which do not need to be pure, are also sup- 
 plied at moderate prices. A list may be had on application. 
 
 Acms : — 
 
 — Acetic, sp. gr. 1' 
 
 Tj • ( cry St. . 
 
 — Boracic, w j 
 
 ' I fused . 
 
 — Citric, cryst. . 
 
 — Muriatic, sp. gr. 1 
 
 — Nitric, sp. gr. 1 
 
 — — fuming, sp. gr. 1 
 • — Oxalic, cryst. 
 
 — Phosphoric, glacial . 
 
 — — solution 
 
 — Sulphuric, sp. gr. 1 
 
 — — fuming 
 
 — Succinic, cryst. . 
 
 — Tartaric, cryst. 
 
 — Gallic, cryst. 
 
 07, oz. 
 
 . oz. 
 , . oz. 
 
 . oz. 
 •13, lb. 
 •22, lb. 
 •52, lb. 
 . . oz. 
 
 . oz. 
 . . oz. 
 •84, lb. 
 
 .lb. 
 , . oz. 
 
 . oz. 
 . . oz. 
 
 d. 
 
 8 
 4 
 6 
 
 8 
 
 9 
 
 6 
 
 1 6 
 
 6 
 
 1 6 
 1 
 
 4 
 6 
 
 5 
 
 Ammonia, liquid, sp. gr. 0'9 . lb. 1 6 
 
 — Carbonate . . . oz. 3 
 
 — Hydrosulphuret, sol. . . oz. 6 
 
 — Muriate . . . . oz. 3 
 
 oz. 
 oz. 
 oz. 
 oz. 
 oz. 
 
 Ammonia, Nitrate, cryst. 
 
 — Oxalate, cryst. 
 
 — Phosphate, cryst. 
 
 — Succinate, cryst. 
 
 — Sulphate, cryst. . 
 Antimony (free from Arsenic) lb 
 Arsenic, metallic . lb. 2 oz 
 Barium, Chloride, cryst. 
 
 — • Sulphuret, cryst. . . 
 
 Barytes, Acetate, cryst. . 
 
 — Caustic, Hydrate, cryst. . 
 • — • Carbonate, precipitated . 
 
 — Nitrate, cryst. 
 Bismuth, Subnitrate (free from 
 
 Arsenic) . . . • 
 Bromine .... 
 
 Cadmium, metallic . . . 
 
 — Carbonate 
 
 — Sulphate, cryst. . . . 
 
 — Sulphuret 
 
 s. d. 
 
 9 
 9 
 
 oz. 
 
 oz. 
 oz. 
 oz. 
 oz. 
 
 oz. 
 oz. 
 oz. 
 oz. 
 oz. 
 oz. 
 
 1 
 
 1 
 
 8 
 
 6 
 
 1 4 
 3 6 
 
 8 
 
1849.] 
 
 GRIFFIN'S SCIENTIFIC CIRCULAR. 
 
 PURE CHEMICAL TESTS— continued. 
 
 
 s. 
 
 d. 
 
 . oz. 
 
 
 
 2 
 
 . oz. 
 
 
 
 2 
 
 . oz. 
 
 
 
 8 
 
 . oz. 
 
 1 
 
 
 
 . . oz. 
 
 
 
 4 
 
 . oz. 
 
 
 
 3 
 
 . . oz. 
 
 1 
 
 
 
 . oz. 
 
 
 
 2 
 
 . 'lb. 
 
 2 
 
 6 
 
 . oz. 
 
 2 
 
 6 
 
 . . oz. 
 
 
 
 2 
 
 L . oz. 
 
 1 
 
 3 
 
 . . oz. 
 
 
 
 3 
 
 . oz. 
 
 
 
 1 
 
 lb. 1 6 
 
 oz. 2 
 
 oz. 2 
 
 oz. 2 
 
 Calcium, Chloride, cryst. 
 
 — Sulphuret 
 Carbon, Sulphuret 
 Copper, Acetate, cryst. . 
 
 — Chloride, cryst. . 
 
 — Nitrate, cryst. 
 
 — Black Oxide 
 
 — Sulphate, cryst. 
 Gold, Chloride, cryst. 
 
 — — solution 
 Indigo, Sulphate, strong 
 Iodine, large crystals 
 Iron. Protochloride . 
 
 — Perchloride, sublimed 
 
 — Persulphate 
 
 — Protosulphate, cryst 
 
 — — Otto's, for Test 
 ing Bleaching Powder 
 
 Lead, in foil . 
 
 — Acetate, cryst. . 
 
 — Carbonate, precipitated. 
 
 For the preparation of 
 pure salts of lead . ) 
 
 — Chromate, fused . . 
 
 — Nitrate, cryst. 
 Lime, Carbonate, precipitated 
 
 — Nitrate, cryst. 
 Litmus ..... 
 Magnesia, Carbonate, precip. . 
 
 — Sulphate, cryst. 
 Mercury, Cyanide, cryst. . . 
 
 — Perchloride, cryst. . 
 
 — Protochloride, cryst. . 
 
 — Protonitrate, cryst. . 
 Microcosmic Salt, cryst. . . 
 Nickel, Soda-Borate 
 Plumbago .... 
 Platinum, Chloride, sol. . . 
 Potash, Antimoniate (test } 
 
 for Soda) . . . ^ 
 Potash, Acetate, cryst. . 
 
 — Carbonate . . . . 
 
 — — nearlj/ jnire 
 
 Crystal Drainer, lierlin Porcelain, 
 5 inches diameter: — 
 
 1747. Shallow, 1^. (kl. 
 
 1748. Deep, 25. 
 
 1749. Electiucal ^Machines and Appahatus 
 
 for Instructive and Entertaining 
 Experiments, in great variety. 
 
 oz. 
 
 
 
 4 
 
 oz. 
 
 
 
 4 
 
 oz. 
 
 
 
 6 
 
 oz. 
 
 
 
 6 
 
 oz. 
 
 
 
 3 
 
 oz. 
 
 
 
 1 
 
 oz. 
 
 4 
 
 
 
 oz. 
 
 1 
 
 
 
 oz. 
 
 1 
 
 
 
 oz. 
 
 1 
 
 
 
 oz. 
 
 
 
 4 
 
 oz. 
 
 1 
 
 6 
 
 oz. 
 
 
 
 2 
 
 oz. 
 
 7 
 
 
 
 oz. 
 
 
 
 9 
 
 oz. 
 
 
 
 6 
 
 oz. 
 
 
 
 9 
 
 oz. 
 
 
 
 2 
 
 Potash, Bicarbonate, cryst. 
 
 — Caustic {lumps) 
 
 — — nearit/ 2)ure in sticks 
 
 — Chlorate, nearly pure, 
 cryst. 
 
 — Nitrate, cryst. 
 
 — Oxalate, neutral, cryst. 
 
 — Superoxalate, cryst. 
 
 — Red Prussiate, cryst. . 
 
 — Sulphate, cryst. 
 
 — Bisulphate, cryst. 
 
 — — fused . 
 Potassium, metallic . 
 
 — Bromide, cryst. 
 
 — Cyanide, fused . 
 
 — Iodide, cryst. . 
 
 — Sulphuret, fused 
 Selenium . . . . 
 Silver, Nitrate, cryst. . . 
 
 — — nearly pure, cryst. 
 Soda, Acetate, cryst. 
 
 — Borate, cryst. 
 — - Caustic, lumps . . . 
 
 — — nearly pure, in sticks 
 
 — — solution, sp. gr. r35, 
 
 — Carbonate, cryst. . . 
 
 — — anhydrous 
 
 — Bicarbonate, cryst. . . 
 
 — Nitrate, cryst. 
 
 — Phosphate, cryst. . . 
 
 — Succinate, cryst. 
 
 — Sulphate, cryst. . . . 
 
 — Sulphite, cryst. 
 
 — Hyposulphi'te,cryst.lb.35. 
 Sodium, metallic 
 
 — Bromide, cryst. . . . 
 Strontian, Carbonate, precip. . 
 
 — Nitrate, cryst. . 
 Strontium, Chloride, cryst. 
 Tin, Protochloride, cryst. . . 
 Zinc, free from Arsenic, in \ 
 
 Marsh's \ 
 
 s. 
 oz. 
 oz. 1 
 oz. 
 lb. 3 
 oz. 
 oz. 
 oz. 
 oz. 
 oz. 1 
 oz. 
 oz. 
 oz. 
 oz.25 
 oz. 4 
 oz. 1 
 oz. 2 
 oz. 
 gr. 
 oz. 7 
 oz. 5 
 
 oz. 
 oz. 
 oz. 1 
 oz. 
 lb. 1 
 lb. 1 
 oz. 
 oz. 
 oz. 
 oz. 
 oz. 3 
 oz. 
 oz. 
 oz. 
 oz.25 
 oz. 4 
 oz. 
 oz. 
 oz. 
 oz. 
 
 d. 
 4 
 
 6 
 
 3 
 2 
 9 
 6 
 4 
 2 
 1 
 1 
 
 
 
 
 4 
 3 
 
 
 3 
 6 
 
 6 
 
 
 3 
 2 
 1 
 3 
 
 1 
 6 
 3 
 
 
 9 
 3 
 3 
 2 
 
 small rods, for 
 apparatus 
 
 oz. 4 
 
 1747. 
 
 1748. 
 
6 GRIFFIN'S SCIENTIFIC CIRCULAR. [May, 
 
 1750. ENCYCLOPEDIA METROPOLITANA. Cheap Re-Issue in Parts. 
 
 The Arts and Sciences complete in 63 Parts. 4to. 
 
 PURE SCIENCES. 
 Part 
 
 1. GENERAL PREFACE to the ENCYCLOPiEDIA METROPOLITANA. 
 
 By H. J. Rose, B.D., Cambri^^ge. 
 GENERAL INTRODUCTION, On METHOD. By S. T. Coleridge. 
 Price Is. 
 
 2. UNIVERSAL GRAMMAR. By Sir J. Stoddart, LL.D. 5s. 
 
 3. LOGIC. By Richard Whately, D.D., Archbishop of Dublin, 2s. 
 
 4. RHETORIC. By Richard Whately, D D., Archbishop of Dublin. 2s. 6^. 
 
 5. GEOMETRY. ByPETERBARLOAV, Esq., F.R.S., Woolwich. 6 Engravings. 3s. 
 
 6. ARITHMETIC. ByGEORGE Peacock, D.D., Dean of Ely. 3 Engravings. 5s. 
 
 7. ALGEBRA and GEOMETRICAL ANALYSIS. By D. Lardner, LL.D., 
 
 F R.S., F.R.S.E. 3s. 6cl. 
 
 8. THEORY of NUMBERS. By Peter Barlow, Esq., F.R.S., Is. 6d. 
 
 9. TRIGONOMETRY. By George Biddle Airy, Esq., M.A., F.R.S., 
 
 Astronomer-Royal. 2s. 6d. 
 
 10. ANALYTICAL GEOMETRY and CONIC SECTIONS. By the Rev. H.P. 
 
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 EXPERIMENTAL PHILOSOPHY. 
 
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 28. ELECTRICITY. Bv the Rev. F. Lunn, M.A., F.R.S. 5 Eng. 5s. 
 
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 33. SOUND, By Sir John F. W. Herschel, Bart., M.A., F.R.S., F.R.S.E. 
 
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 42. POETRY. By John Hughes, Esq., M.A., Oriel College, Oxford. Is. 6d. 
 
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 44. ENGRAVING. By the Rev. John Lindsay, M.A. 4 Engravings. 3s. 6d. 
 
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 1752. FOSSIL INFUSORIA for EXAMINATION by the MICROSCOPE: 
 
 A Cabinet containing Twelve Specimens of Minerals, — Siliceous, Calcare- 
 ous, Carboniferous, Ferruginous, — consisting principally of the Skeletons 
 of Infusoria. Price, including 12 bottles, Is. Qd. 
 
 Names of the Specimens in the Cabinet: — 
 
 1. 
 
 6. 
 
 Infusorial Earth ; Infusorien Erde ; 
 
 Heine Kicselerde; Pure Silica; Kiesel- 
 
 guhr ; Goulir Siliceux. — From Fran- 
 
 zensbrunnen in Bohemia. 
 The same. — From Gossa in Bohemia. 
 The same. — From Obero in Luneberg. 
 Infusorial Earth ; Infusorienerde. — 
 
 From the Thiergarten in Berlin. 
 Polishing Slate ; Polierschiefer ; Infuso- 
 
 rienschiefer; Schiste tripoleen. — From 
 
 Bilin in Bohemia. 
 The same. — From Habichtswald, near 
 
 Cassel, in Germany. 
 
 7. Semi-Opal ; Halb-Opal ; Quarz resinite 
 
 xyloide. Consisting of Brown Coal 
 altered by Volcanic action.- — From 
 Bilin, near Toplitz, in Bhoemia. 
 
 8. Flint ; Feuerstein ; Pierre de fusil. — 
 
 From Funen in Denmark. 
 
 9. Chalk; Kreide; Craie. — From Zealand. 
 
 10. The sa7ne. — From Kent, in England. 
 
 11. Paper Coal; Dysodil ; Houille papy- 
 
 racee. — From Salzhausen in Hcssia. 
 
 12. Bog Iron Ore ; Raseneisenstein ; Fer 
 
 hydrate limoneux — From Lieben- 
 werda in Saxony. 
 
 1753. 
 
 1754. 
 
 1755. 
 
 1756. 
 
 1757. 
 
 1758, 
 
 GAS CONDENSERS, or SUBSTITUTE for WOULFF'S APPA- 
 RATUS, in small experiments. 
 
 U-shaped, Fig. 1753, 
 
 small, 17 inches by 
 
 I inch. Is. 6d. 
 U-shaped, Fig. 1753, 
 
 large, 21 inches by 1 
 
 inch, 2^. 6d. 
 V-shaped, small, 10 in- 
 ches by J inch, with 
 
 legs of unequal length. 
 
 Is. 
 V-shaped, Fig. 1756, 
 
 large, 15 inches by f 
 
 inch, with equal legs, 
 
 Is. 3d. 
 
 Without Fittings, at the above Pri:es. 
 A strong fj -shaped Conducting Tube, with ground ends, for connecting 
 
 the U-shaped Condenser to a gas bottle, 9d. 
 A strong f) -shaped Conducting Tube, with ground ends, for connecting 
 
 the V-shaped Condenser to a gas bottle, 9d. 
 
 The use of the above Apparatus is illustrated in Chemical Recreations, p. 302. 
 When the Condenser contains a small quantity of Avater, and is immersed in iced- 
 water contained in a beaker, a saturated solution is easily procured of any gas that 
 is absorbable by water, such as Ammonia. 
 
 This Apparatus also serves for washing or drying gases, or for trying their action 
 on different solutions. See No. 1729. 
 
 1753. 
 
 1756. 
 
1849.] GRIFFIN'S SCIENTIFIC CIRCULAR. 9 
 
 GEOLOGY.— COLLECTIONS of FOSSILS, arranged in the order in 
 which they occur in the Strata composing the crusts of the earth, accord- 
 ing to the system described in the Lethaea Geoanostica of Puofkssor 
 BiioNN. With an ample descriptive printed Catalogue in French, 
 English, and German, containing numerous synonyms. 
 
 These Collections contain Fossils belonging to all formations, and from many 
 localities, and in such variety as could only be obtained by the assiduous researches 
 of many years, attended by very great expense. The utmost pains has been taken 
 by a competent Naturalist (a German Professor) to determine and name the speci- 
 mens with accuracy. The Catalogue sbows the prevalent name of each Fossil, its 
 most important synonyms, with their authorities, and its stratographical and geo- 
 graphical locality. The arrangement of the Catalogue agrees strictly with that of 
 Bkonn's Lethaea Geognostica, the most useful book on Organic Remains that has 
 yet been published. 
 
 Prices of the Collections, with printed Catalogues : — 
 
 1759. Three hundred Specimens, 15/. 
 
 1760. Five hundred Specimens, "2oL 
 
 The following Collections of Fossils have written Catalogues : — 
 
 1761. One hundred Specimens, 3/. Zs. 
 
 1762. One hundred and fifty Specimens, 61. 5s. 
 
 GEOLOGICAL COLLECTIONS, containing Specimens of ROCKS, 
 with their CHARACTERISTIC FOSSILS. 
 
 These Collections .are adapted either for private study, or for the use of lecturers, 
 and have been prepared with great attention to their scientific accuracy. The 
 Rocks are disposed in the oi'der of their natural position relative to one another ; 
 and the Fossils, being those most characteristic of the diflerent Rocks, and in 
 number about one-third of the entire Collection, are placed just after the Rocks to 
 which they belong. The Collections are accompanied with Pkintkd Cat.vlogues 
 containing the synonymous names in French, German, and English, with short 
 remarks on the localities and peculiarities of the different formations. 
 
 The size of the Cut Specimens of Rocks is 9 squai-e inches, namely, 3i inches by 
 23 inches, very neatly cut, Iresh, and clean. 
 
 1763. Collection of six hundred Specimens, 251. 
 
 1764. Collection of five hundred Specimens, 20/. 
 
 GRADUATED GLASS INSTRUMENTS.— We beg to inform our 
 Chemical friends, that having completed our machinery for the gradua- 
 tion of Glass Apparatus, we can now undertake to supply Glass Measures 
 graduated with the utmost accuracy to any desired scale ; namely, 
 Alcalimeters, Acidimeters, Chlorimeters, Eudiometers, Gas Tubes, 
 Liquid Measures, &c., ;;raduated to English Imperial Measure, Cubic 
 Inches, or French jMeasures, or any divisions or multiples of these 
 measures, decimal or arbitrary. 
 
 1765. GAY-LUSSAC'S CENTESIMAL ALCOIIOLOMKTKK, a Glass 
 
 Spindle, form of ///. 1768, scale 0° to 100 , each Degree showing 1 
 per cent, of })ure Alcohol in any mixture of Spirit and Water, at the 
 temperature of 15° Centigrade, or 59° Fahrenheit, in a pasteboard case, 
 45. 6d. 
 
10 
 
 GRIFFIN'S SCIENTIFIC CIRCULAR. 
 
 [Mat, 
 
 HYDROMETERS, in the form of Glass Spindles, Fig. 1768, for deter- 
 mining the Specific Gravity of all Solutions from sp. gr. 700 to sp. 
 gr. 2'000, water being considered = 1*000. The delicacy of this in- 
 strument increases with the number of Spindles contained in the set. 
 The entire scale, from '700 to 2'000, may be contained on one Spindle, 
 or on 2, 3, 4, 5, or 7 Spindles. 
 
 One Spindle, scale from 070G° to 1-000° by degrees of '005°, and from 
 1-000° to 1-900" by degrees of -010° ; namely, -805°, "810°, and 1010°, 
 1020°, &c. With a Solution Tube, Fig. 1766, and a pasteboard box, Qs. 
 
 1766. 
 
 1767. 
 
 1768. 
 
 1769. 
 
 1770. 
 
 1771. 
 
 A useful instrument for preliminary trials, for students, or for common use when 
 approximate indications are sufficient. It shows the specific gravity of all liquids, 
 fn.m alcohol to oil of vitriol. Each degree above 1000° is equal in range to 2° of 
 Twaddell ; below 1000°, each degree in equal to 1° of Twaddell. 
 
 Sets of Hydrometers in Polished Wooden Boxes, Fig. 1769. 
 
 Box containing Two Spindles, form of Fig. 1767, with Thermometer, and 
 a Trial Jar for the Solutions, 1/. 4*'. 
 
 Spindle «, scale '700° to 1-200°, by '010^ 
 
 Spindle b, scale 1-200° to 2*000°, by -010°. 
 
 Box containing Three Spindles, form of 
 Fig. 1768, with Thermometer and Trial 
 Jar for Solutions, 1^. 16^. 
 
 Spindle a, scale -700° to 1-000°, by -002°. 
 
 Spindle h, scale 1-000° to 1 400°, by -002°. 
 
 Spindle c, scale 1-400° to 1-970°, by "002°. 
 
 Box containing Four Spindles, with 
 Thermometer and Trial Jar for Solu- 
 tions, Fig. 1769, 2/. 2s. 
 
 Spindle a, scale "700° to I'OOO", by '002". 
 
 Spindle b, scale 1-000° to 1-300°, by -001°. 
 
 Spindle c, scale 1-300° to 1-600°, by -001°. 
 
 Spindle d, scale 1-600° to 1-950°, by -001°. 
 
 Box containing Five Spindles, with 
 Thermometer and Trial Jar for Solu- 
 tions, 21. 125. Qd. 
 
 Spindle a, scale '700° to 1*000°, by -001°. 
 
 Spindle b, scale 1000° to 1200°, by '001°. 
 
 Spindle c, scale 1*200° to 1-400% by -001°. 
 
 Spindle d, scale 1-400° to 1-640°, by *001°. 
 
 Spindle e, scale 1-640° to 1*900°, by -001°. 
 
 Box containing Seven Spindles, with 
 Thermometer and Trial Jar for Solu- 
 tions, 3^. 3.9. 
 
 Spindle a, scale '700° to '850°, by -001°. 
 
 Spindle b, scale '850° to 1*000°, by *001°. 
 
 Spindle c, scale 1*000° to 1*200°, by *001°. 
 
 Spindle d, scale 1*200° to 1*400°, by -001°. 
 
 Spindle e, scale 1*400° to 1*600°, by *001°. 
 
 Spindle /, scale 1*600° to 1*800°, by -001°. 
 
 Spindle^, scale 1*800° to 2*000°, by -001°. 
 
 In all the above Spindles, where the scale rises by steps of *00P, each marked 
 DEGREE is equal to one-Jifth of a degree of Twaddell's Hydrometer. See the 
 Note to No. 1795. 
 
 V 
 
1849.] GRIFFIN'S SCIENTIFIC CIRCULAR. 11 
 
 Separate Spindles, each in a pasteboard box, at the prices quoted: — 
 
 1772. Scale '700° to 1-000°, by 005°, 6.9. 
 ] 773. Scale, 1-000° to 2-000°, by 010°, ds. 6d. 
 
 Both Spindles in the form of Fif/. 1767. Each has a trial tube. Owins? to the 
 narrowness of these Spinoles, ver>/ small quantities of solution can be tried. In 
 order that the Spindle may act freely in the narrow trial tube, the funnel at the 
 top must be nearly filled with the solution. 
 
 1774. Scale, -700° to 1-000°, by '002°, Fig. 1768, 65. iyd. 
 
 1775. Scale, 1-000° to 2-000°, by '010°, Fig. 1768, 7^. 
 
 1776. Scale, -700° to 1*000°, by -001°, Fig. 1768, 9^. 
 
 1777. Scale, 1-000° to 1-350°, by -005°, Fig. 1768, 65. 
 
 1778. Scale, 1-350° to 1-900°, by -005°, Fig. 1768, 6.s-. 
 
 1779. Scale, 1-000° to 1-300°, by -002°, Fig. 1768, Qs. Qd. 
 
 1780. Scale, 1*300° to 1-600°, by '002°, Fig. 1768, 65. 6^. 
 
 1781. Scale, 1-600° to 1-900°, by -002°, Fig. 1768, 6s. 6c?. 
 
 1782. Scale, 1-000° to 1-020°, by -0005°, Fig. 1768, 95. 
 
 No. 1782 is for determining the density of Sours, &c. Very delicate. 
 
 Hydrometer Spindles, which have a Fahrenheit's Thermometer con- 
 tained inside the Cylinder, Fig. 1847. Each in a pasteboard box, at 
 the prices quoted : — 
 
 1783. Scale, -700° to 1000°, by -002°, IO5. 6(7. 
 
 1784. Scale, 1-000° to 1-350°, by -002°, lOs. 6d. 
 
 1785. Scale, 1-350° to 1-900°, by -002°, 10*. 6d. 
 
 The Hydrometer Spindles, with a scale from 1*000° to 1-350°, by -002^ , 
 may be had in the following forms : — 
 
 1786. The Spindle alone. Fig. 1768, in a pasteboard box, 6s. 
 
 1787. The Spindle, with a Trial Jar for Solutions, in a polished wooden box, 11. 
 
 1788. The Spindle, with a Thermometer within it. Fig. 1847, in a pasteboard 
 
 box, 10s. 6d. 
 
 1789. The Spindle, with Thermometer within it, and a Trial Jar for Solutions, 
 
 in a polished wooden box, 11. 4s. 
 
 All other forms of Hydrometer, — Nicholson's, Beaume's, Fahrenheit's, &c.; 
 also Alcoholometers, Urinometers, Volumeters, &c. 
 
 1790. HYDROMETERS (TWADDELL'S), Warranted Accuratk, Griffin's 
 
 Improved Form, in which the round bulb is replaced by a pear-shaped 
 body, or a cylinder. The advantages of these forms over the bulb are, 
 greater durability, and the power of taking the density of a smaller 
 quaiititj/ of liquid. 
 
 Price 0/ Single Spindles, each in a Pasteboard Box. 
 
 No. 1— 0° to 24° 
 
 2— 24° to 48° . 
 
 3— 48° to 74° 
 
 4— 74° to 102° . 
 5—102'* to 138" 
 6 — 138° to 170° . 
 
 1791. Set of six Cylindrical Spindles, in six pasteboard cases, IS.s-. 
 
 1792. Set of six Conical ditto ditto 1/. 1*. 
 
 Cjlindrical 
 .1. d. 
 
 Form 
 
 . 2 
 
 (5 
 
 . 
 
 . 2 
 
 6 
 
 , 
 
 . 3 
 
 
 
 
 . 3 
 
 
 
 
 . 3 
 
 () 
 
 , 
 
 . 3 
 
 6 
 
 , 
 
 rear-shaj) 
 s. 
 
 . 3 
 
 ed I'omi 
 d. 
 
 
 . . 3 
 
 
 
 . 3 
 . . 3 
 
 6 
 
 . 4 
 
 
 
 . . 4 
 
 
 
12 
 
 GRIFFIN'S SCIENTIFIC CIRCULAR. 
 
 [May, 
 
 1793. 
 
 1794. 
 1795. 
 
 Set of six Cylindrical Spindles, in a polished wood box, in the style of 
 
 fig. 1769, il. Ss. 
 Set of six Conical Spindles, ditto. 1/. lis. Qd. 
 
 Set of six Cylindrical Spindles, of a small size, for use in Chemical 
 
 Researches, where only small quantities of Liquid are obtained, in a 
 
 mahogany box, 1/. \0s. 
 
 As the speciiic gravities of liquids are commonlj^ denoted in books, in reference to 
 hydrometers which indicate the direct specific gravity of liquids, in comparison 
 with that of water, taken as a standard, and denoted by I'OOO, whilst manufacturers 
 in this country are much in the habit of speaking of specific gravities in reference to 
 the scale adopted by Twaddell, it may be useful to show the relation of the degrees 
 marked on TioaddelV s Hydrometers^ to those which express the direct specific 
 gravity of a liquid. The necessary calculations are made by means of the following 
 Formulae : — 
 
 Let a = any degree of Twaddell' s Hydrometer. 
 
 X z=z specific gravity in relation to water taken at 1 -000. 
 Formula I. — To convert Twaddell's degrees into sp. gr. a; = 1 -|- (a x '005) 
 
 X— 1 
 Formula 2. — To convert sp. gr. into degrees of Twaddell. a =. .^^^^ 
 
 Example 1. — If a liquid marks 5 of Twaddell, what is its sp. gr. < 
 
 By Formula 1.— Sp. gr. = 1 + (5 x -005) = 1-025. 
 
 Example 2. — If a liquid has the sp. gr. of 1-830, what degree of Twaddell's scale 
 will that indicate ? 
 
 By Formula 2.— Twaddell = L^^_"IL^ = ^ = 170. 
 
 •005 "005 
 
 Hence 5 of Twaddell = specific gravity of 1-025. And 170 of Twaddell^ 
 specific gravity of r850. 
 
 TABLE OF SPECIFIC GRAVITIES INDICATED BY TWADDELL's SCALE. 
 
 Twaddell. 
 
 Sp. Gr. 
 
 Twaddell. 
 
 Sp. Gr. 
 
 TwaddeU. 
 
 Sp. Gr. 
 
 Twaddell. 
 
 Sp. Gr. 
 
 
 
 1000 
 
 50 
 
 1250 
 
 100 
 
 1500 
 
 150 
 
 1750 
 
 10 
 
 1050 
 
 60 
 
 1300 
 
 110 
 
 1550 
 
 160 
 
 1800 
 
 20 
 
 1100 
 
 70 
 
 1350 
 
 120 
 
 1600 
 
 170 
 
 1850 
 
 30 
 
 1150 
 
 80 
 
 J400 
 
 130 
 
 1650 
 
 180 
 
 1900 
 
 40 
 
 1200 
 
 90 
 
 1450 
 
 140 
 
 1700 
 
 190 
 
 1950 
 
 METALLURGIC MINERALOGY.— Collections of Ores of the Prin- 
 cipal Metals, with a Catalogue of Names and Localities. 
 
 1796. One hundred Specimens, 3 square inches, Al. 4s. 
 
 1797. One hundred Specimens, 4 square inches, 5^. 5s. 
 
 1798. Fifty Specimens, 6 square inches, 3/. 13s. 6c?. 
 
 1799. 
 1800. 
 1801. 
 
 1802. 
 
 MINERALOGY. — COLLECTIONS of SPECIMENS of SIMPLE 
 MINERALS, arranged in systematic order, according to the last edition 
 of William Phillips's Elementary Introduction to Mineralogy. The 
 Specimens are well selected, fresh, clean, characteristic, and accurately 
 named. 
 
 Two hundred Specimens, size 4 square inches, 51. 5s. 
 
 Three hundred Specimens, ditto 7/. 71. 
 
 FoMY hundred Specimens, size 6 square inches, 14^. 
 
 Five hundred Specimens, ditto 201. 
 
1849.] GRIFFIN'S SCIENTIFIC CIRCULAR. 13 
 
 1803. GRIFFIN'S CABINET for Bkginners in the Study of Mineralogy and 
 
 Geology, 2^. 2s. 
 
 1804. Ditto, a superior collection, 21. 10^. 
 
 This collection contains fifty specimens of simple Minerals, fifty specimens of 
 Rocks, and fifteen models of Crystals, contained in a strong? and neat pasteboard 
 Cabinet, with five divided trays. It is accompanied by a book containing an Intro- 
 duction to the Sciences of Mineralogy and Geology, with a particular descrip'ion of 
 every specimen contained in the Cabinet. The size of the s})ecimens in the Cabinet 
 at 21. 2s. is two square inches. Those in the Cabinet at 21. lOs. are a little larger. 
 The Book may be had separately, ^^r/ce 0)ie Shilling. 
 
 SMALL COLLECTIONS OF MINERALS (all with Catalogues). 
 
 1805. Eighty Fragments of Minerals for Exercises with the Blowpipe, &c., 
 
 with a printed Catalogue, in a box, 5^. 
 
 1806. Fifty-four Minerals, size one-inch square, Qs. 
 
 1807. The same in a japanned metal divided box, 95. 
 
 1808. Fifty-four Minerals, size two inches square, 9s. 
 
 1809. The same, in a handsome pasteboard divided box, \5s. 
 
 1810. One Hundred Minerals, one inch square, 15^. 
 
 1811. Fifty-four Specimens of Rocks and Fossils, size one inch square, Qs. 
 
 1812. The same, in a japanned metal divided box, 95. 
 
 1813. Fifty-four Specimens of Rocks and Fossils, size two inches square, 95. 
 
 1814. The same, in a handsome pasteboard divided box, lo5. 
 
 1815. ]\IoHs's Dkgrees of Hardness of Minerals, for Comparative Trials, 9 
 
 specimens in a box, with a file, 16s. 
 
 1816. Ditto, a smaller collection, with a file, 85. 
 
 1817. Von Kork.ll's Degrees of Fusibility of Minerals, for Comparative 
 
 Trial before the Blowpipe, 6 specimens in a box, 55. 
 
 jNIINERALS, Examination of, to Detect Metals. 
 
 Collection of Chemical Apparatus and Purr Chemical Tests, for the 
 Qualitative Analysis of Minerals. The Instruments all of the best 
 quality and the smallest size, comprehending a complete Blowpipe 
 Apparatus, and also Apparatus for testing in the wet way. The wliole 
 aftbrds the means of separating the Constituents of any ^Mineral, and 
 effecting a complete qualitative analysis. 
 
 This Collection is recommended to the attention of Naval and Military Officers, 
 Civil Engineers, Miners, Travelling Mineralogists, Colonial Agents, &c. It con- 
 tains, in the smallest possible space, the means of deciding whether a given mineral 
 does or does not contain a metal, and also ichat metal it is. 
 
 1818. Price of the Collection, in a strong iNIahogany Cabinet, 21/. 
 
 1819. The Apparatus without the Cabinet, 16/. I65. 
 
 1820. In some circumstances it will be useful to have a Rough Case, containing 
 
 an extra supply of such articles as are liable to break, and of such Tests 
 (Acids, &c.) as are used in considerable quantities. A sum of 3/. to 5/. 
 may be allowed for such a Supplement. 
 
 1821. An addition of 5/. or 10/. will include the cost of a Portable Balance, and 
 
 such other articles as will enable the operator to effect Quantitative 
 Analyses of the Minerals submitted to examination. 
 
.14 GRIFFIN'S SCI 
 
 ENTIFIC CIRCULAR. 
 
 [M 
 
 iY, 
 
 COLLECTION OF APPARATUS AND TESTS, suitable 
 
 for the 
 
 Examination of jMinerals, 
 
 when the object is simply to identify them, 
 
 and not to sej^arate their Constituents : — 
 
 
 1 
 
 1822. Price, without a Cabinet, 61. 
 
 65. 
 
 
 
 1823. Price, with a Mahogany Cabinet, 8^. 85. 
 
 
 
 1824. MINERALS for ANALYSIS, including some that yield 
 
 RARE 
 
 CHEMICAL ELEMENTS. 
 
 
 1 
 
 Price per 
 
 oz. 
 
 -. Price per 
 
 oz. 
 
 Arsenic. s. 
 
 d. 
 
 Lithium. 
 
 s. 
 
 d. 
 
 Native Arsenic, Andreasherg . 
 
 6 
 
 Lepidolite, Rose Mica 
 
 . 
 
 3 
 
 Orpiment . . . . . 
 
 4 
 
 — in lumps 
 
 . 
 
 3 
 
 Realgar 
 
 2 
 
 Petalite .... 
 
 . 
 
 6 
 
 Arsenical Iron (Mispickel) . . 
 
 6 
 
 Magnesium. 
 
 
 
 Bismuth. 
 
 
 Magnesite, Bohemia 
 
 . 
 
 2 
 
 Native Bismuth, Saxony . . 
 
 6 
 
 Bitierspar, Tyrol 
 
 . 
 
 6 
 
 Antimony. 
 
 
 Manganese, 
 
 
 
 Antimony Feather Ore . . . 
 
 4 
 
 Grey Manganese . 
 
 . 
 
 2 
 
 Sulphuret of Antimony . . 
 
 1 
 
 Psilomelane 
 
 . 
 
 2 
 
 Barium. 
 
 
 Pyrolusite .... 
 
 . 
 
 2 
 
 Sulphate of Barytes, Arran . . 
 
 1 
 
 Mercury. 
 
 
 
 Cadmium. 
 
 
 Sulphuret of Mercury (Cinna 
 
 - 
 
 
 Cadmiferous Blende . . .0 
 
 6 
 
 bar), Deux Fonts . 
 
 . 
 
 6 
 
 Cerium. 
 
 
 Molybdenum. 
 
 
 
 Cerite, containing Cerium, Lan- 
 
 
 Sulphuret of Molybdenum . 
 
 . 1 
 
 
 
 thanium, and Didymium . . 1 
 
 
 
 Moiybdate of lead 
 
 . 
 
 6 
 
 Chromium. 
 
 
 Nickel. 
 
 
 
 Chrome Iron Ore . . .0 
 
 2 
 
 Antimonial Nickel 
 
 . 
 
 6 
 
 Cobalt. 
 
 
 Arsenical Nickel 
 
 . 
 
 6 
 
 Arsenical Cobalt . . . . 
 
 4 
 
 Osmium. 
 
 
 
 Copper. 
 
 
 Osmium-Iridium . 
 
 . 25 
 
 
 
 Grey Copper, Falilerz . . 
 
 4 
 
 Selenium. 
 
 
 
 Copper Pyrites, Cornwall . . 
 
 4 
 
 Seleniuret of Lead 
 
 . 10 
 
 
 
 Malachite, Siberia . . .1 
 
 
 
 Strontium. 
 
 
 
 Fluorine. 
 
 
 Sulphate of Strontium, Saxony 
 
 . 
 
 2 
 
 Fluorspar, free from Silica . . 
 
 1 
 
 Tantalum. 
 
 
 
 Glucinum. 
 
 
 Tantalite .... 
 
 . 10 
 
 
 
 Beryl 
 
 6 
 
 Tellurium. 
 
 
 
 Iron. 
 
 
 Foliated Tellurium . 
 
 . 16 
 
 
 
 Native Loadstone . . . 
 
 6 
 
 Titanium. 
 
 
 
 Clay Iron-stone, Glasgow . . 
 
 2 
 
 Titaniferous Iron . 
 
 . 
 
 4 
 
 Pea Iron Ore . . . .0 
 
 2 
 
 Rutile .... 
 
 . 
 
 9 
 
 Red Iron Ore . . . . 
 
 3 Tungstenum. 
 
 
 
 Brown Iron Ore, Amherg . 
 
 3 
 
 Tungstate of Iron (Wolfram) 
 
 . 
 
 3 
 
 Carbonate of Iron, Bieher . . 
 
 4 
 
 Tin. 
 
 
 
 Iron Pyrites . . . . 
 
 1 
 
 Oxide of Tin, Cornwall 
 
 . 
 
 4 
 
 Lead. 
 
 
 Uranium. 
 
 
 
 Galena, Lead Hills, Scotland . 
 
 1 
 
 Pitch Blende . 
 
 . 
 
 6 
 
 Carbonate of Lead, Freiberg . 
 
 4 
 
 Zinc 
 
 
 
 Lime. 
 
 
 Zinc Blende, Hartz 
 
 . 
 
 6 
 
 Calcareous Spar, Dumbartonshire 
 
 2 
 
 Cadmiferous Blende . 
 
 . 
 
 6 
 
 Gypsum, hydrate, Selenite . 
 
 3 
 
 Calamine .... 
 
 . 
 
 2 
 
1849.] 
 
 GRIFFIN'S SCIENTIFIC CIRCULAR 
 
 1.5 
 
 MORTARS AND PESTLES, AGATE, a superior assortment, recently 
 received from Germany. The prices vary according to the soundness 
 of the Agate, as well as the Size and Form. 
 
 1825. 
 
 Diameter. 
 1.^ inches . 
 
 . 7 
 
 Price. 
 d. s. 
 
 6 to 9 
 
 d. 
 
 
 1830. 
 
 Diameter. 
 
 2| inches . 
 
 £. 
 
 . 
 
 Price. 
 *. die. 
 18 to 1 
 
 t. 
 
 4 
 
 1826. 
 
 If inches 
 
 . 9 
 
 Oto 10 
 
 
 
 1831. 
 
 3 inches 
 
 . 1 
 
 6 to 1 
 
 10 
 
 1827. 
 
 2 inches . 
 
 . 10 
 
 Oto 12 
 
 
 
 1832. 
 
 3^ inches 
 
 . 1 
 
 10 to 1 
 
 13 
 
 1828. 
 
 2^ inches 
 
 . 12 
 
 Oto 14 
 
 
 
 1833. 
 
 3^ inches 
 
 . 1 
 
 14 to 1 
 
 16 
 
 1829. 
 
 2^ inches . 
 
 . 14 
 
 to 18 
 
 
 
 1834. 
 
 41 inches . 
 
 . 4 
 
 
 
 
 ORGANIC ANALYSIS, Liebig's Apparatus for. 
 
 All the Apparatus for Organic Analysis made in Germany after the latest 
 and most approved patterns. See General Catalogue^ pp. 37 and 72. 
 
 1835. Combustion Tube, in lengths of 3 feet, of hard white Bohemian 
 
 glass, imported direct, and icarranted to he of the best qualitj/, per lb. 
 25. Qd., or 25 lb. for 50^. 
 
 1836. Horsford's Improvement of Varrentrapp and Will's Apparatus for the 
 
 estimation of Nitrogen ; best make, thin light German glass, \s. 6d. 
 
 1837. Liebig's Potash Bulbs, of German glass, very light, in a pasteboard box. 
 
 fip. 1837 m, 2s. 
 
 1838. Liebig's Chloride of Calcium Tube, one bulb, straight, very light, 
 
 fp. 1837 b, 6d. 
 
 1839. Liebig's New Desiccating Tube, U-shape, with a bulb, fitted with cork 
 
 and tube. Is. 6c?. 
 
 ^^====»-if=«f==r=^ 
 
 Fi(j. 1837. 
 
 1840. 
 
 Stenhouse's Improved Combustion Furnace for Organic Analysis, 55. 
 
 By making a greater number of supports, and turning over the edge of each, 
 the cutting of the softened tube is prevented. 
 
 1841. Leaf Copper to envelope the Combustion Tube when heated for the 
 
 Nitrogen process, to prevent its flexure, 35. per lb. 
 
 1842. Pure Metallic Copper, in filaments of extreme thinness, 85. per lb. 
 
 1843. A Complete Set of Liebig's Tube Apparatus for Organic Analysis, com- 
 
 prising 18 articles, I85. ^ 
 
 1844. Liebig's Instructions for Organic Analysis, translated % Professor 
 
 Gregory, 25. (id. 
 
 1845. WATER TEST, Professor Clark's.— Standard Solutions and Appara- 
 tus for Determining the Haroness of Water, according to the Process 
 of Professor Clark. Particulars wiU be given in our next Circular. 
 
16 
 
 GRIFFIN'S SCIENTIFIC CIRCULAR. 
 
 [May. 
 
 SACCHAROMETER (Hermbstadt's). 
 
 This Instrument has been found of grf at use by persons ena^aged in the 
 Manufacture of Sugar fi-om Cane Juice, and also by Sugar Re- 
 finers. It is a glass spindle, of the form of Fig. 1847, containing two 
 ■written scales. One of these shows the specific gravity of a solution of 
 sugar, from I'OOO (= pure water) to 1-400 (= saturated solution of sugar 
 at 64:0 Fahr.) The other scale goes from O^ to To". It shows the |;er- 
 centage of sugar, or the proportion, by weight, in 100 parts by weight of 
 the syrup. That is to say, it shows how many pounds of sugar are con- 
 tained in 100 pounds of the syrup. 
 
 The following Varieties may he had : — 
 The Spindle alone, without Thermometer, form oijig. 1768, 8.?. 
 The Spindle alone, with a Thermometer inclosed in the Cylinder, 
 as shown in fig. 1847; — the scale of the Thermometer written 
 on paper, 14i\ 
 The same, with the scale of the Thermometer painted on milk 
 glass, 165. 
 
 The above are in round pasteboard boxes. 
 The following in square polished wooden boxes : — 
 The Spindle having a Thermometer with paper scale, and a trial- 
 jar for the syrup, in a polished wooden box, in the style oi fig. 
 1769, 285. 
 1850, The same, with a glass scale to the Thermometer, 30s. 
 
 ^•1^.1847. 
 
 1846. 
 1847. 
 
 1848. 
 
 1849. 
 
 1860. 
 
 1861. 
 
 TEST TUBES of the 
 closed and properly 
 rounded at one end, 
 and bordered at the 
 mouth. Fig. 1851. 
 Well annealed. 
 
 Best Thin Hard White Bohemian Glass, 
 
 Fig. 1851. 
 
 Width across the middle. 
 
 
 Length 
 
 in Inches 
 
 
 Per Dozen. 
 
 1851. 
 
 Quarter-inch 
 
 1 
 
 u 
 
 2 
 
 
 s. d. 
 . 1 
 
 1852. 
 
 One-third inch . . 
 
 2 
 
 2| 
 
 3 
 
 — 
 
 . ..16 
 
 1853. 
 
 Half inch 
 
 2^ 
 
 3 
 
 oh 
 
 — 
 
 . 2 
 
 1854. 
 
 Half inch . . . 
 
 4 
 
 5 
 
 5i 
 
 — 
 
 ..26 
 
 1855. 
 
 Three-quarter inch 
 
 3 
 
 31 
 
 4 
 
 4^ 
 
 ..30 
 
 1856. 
 
 Three-quarter inch 
 
 5 
 
 ^ 
 
 6 
 
 — 
 
 ..40 
 
 1857. 
 
 One inch 
 
 3 
 
 4 
 
 5 
 
 6 
 
 . 5 
 
 1858. 
 
 One inch . . . 
 
 6^ 
 
 7 
 
 7^ 
 
 — 
 
 ..60 
 
 1859. 
 
 Above one inch . 
 
 6 
 
 7 
 
 8 
 
 — 
 
 . 8 
 
 Test Tubes : a nest of Six, from 4 to 7 inches long, in a pasteboard box, 
 
 for^ravelling, 1.9. (5d. 
 Test Tubes, Brushes for cleaning, — various sizes, each, Ad. 
 
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 Printers, at their Office in Lombvird Street, in the Precinct of Whitefriars, in the City of Londo'i, 
 and I'ubli'hed hy .John .Joseph Griftin ik Company, Chemical Museum, 53, Baker Street, Portman 
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The Rev. EDWARD SMEDLEY, M.A., late Fellow of Sidney College, Cambridge. 
 The Rev. HUGH JAMES ROSE, B.D., late Principal of King's College, London. 
 Tlie Rev, HENRY JOHN ROSE, BJ)., late Fello\y of St. John's CoUege, Cambridge. 
 
 PRINCfPAL CONTRIBUTORS. 
 
 
 
 f AiET, G. B., Esq., A.M., F.R,a Astxaiw 
 '* mer Royal. 
 
 Arnold, Rev. Thomas, D.D., Rngby. 
 
 Babbage, C, Esq., A.M., FJl^S. 
 
 Barlow, Peter, Esq., F.R.S. 
 
 Bell, T., Esq., F.L.S. - 
 
 Blakkslet, Rev. J. W., M.A. 
 
 
 '^^/S^i )f) Blomfield, C- J.,D.D.,Bishopof Ixmdon. 
 , ^ Xi BoNNTCASTLE, Captain, Royal Engineers. 
 
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 l-S'J 
 
 
 BOWMAK, W., Esq., F.R.S. 
 Brooke, H. J., Esq., F.R.S., F.LJ?. 
 Browne, Rev, R, W,, M.A„ Professor 
 of Classical Literature* King's College, 
 London. 
 
 Browne, Rev, R. L., M.A. 
 
 Carwitiien, J. K. S., B.D. 
 
 Clark, F, Le Gros, Esq. 
 
 Coleridge, Samuel Taylor. 
 
 CoOLET, W. D., Esq., MA„ Trinity Col- 
 lege, Dublin, 
 
 CoRRiE, Rev. G. E., B.D., Norrfeian Pro- 
 fessor of Divinity, Cambridge. 
 
 Cox, Rev. F. A., D.D., L.L.D. 
 
 Daubent, C. G. B., M.D., Professor of 
 Botany and Chemistry, Oxford. 
 
 De Morgan, A., Esq., Professor oS Ma- 
 thematics, University College. 
 
 Donaldson, T, L., Esq., Professor of 
 Architecture, University College. 
 
 Don, G., Esq., F.L.S. 
 
 DowLiNG, Rev, J. G., M.A. 
 
 Graves, J. T„ M.A., F.R.S. 
 
 Gray, J. E., Esq., F.L.S. 
 
 GWILT, J., Esq., F.R.S. 
 
 Hale, Ven. Archdeacon, Charter House. 
 
 Hall, Rev. T. G., M.A, 
 
 HAinLTON, Rev. H. P., M.A., F.R.S., 
 
 Hampden, R. D., D J>., Bishop of Here- 
 ford. 
 
 Harvet, G., Esq,, F,R.S., F.G,S, 
 
 Heescitel, Sir John F. W„ M.A,, F.R.S. 
 
 Hinds, S., D.I)., Bishop of Norwich. 
 
 Hood, Cliarlcs, F.R.S. 
 
 Horne, Rev. T. Hartwell, B.D. 
 
 James, J. T., D.D., Bishop of Calcutta. 
 
 Jeeb, R., Esq., Barrister-at-Law. 
 
 JeremiEjRgv, J. A„ M.A.1 Haileylmry. 
 
 Johnson, G., Esq., M.D. 
 
 Katejs. Captain, F.R.S. 
 
 Lardner, Dionysius, LL.D. 
 Levy, A., Esq., MA., F.G.S 
 Lindsay, Rev. J., M.A. 
 Lowndes, W., Esq., M.A., Q.C. 
 LuNN, Rev. F., M.A., F.R.S. 
 Lyall, Rev. Dr., Dean of Canterbury 
 McCaul, a., D.D., Profeaaor of Hebrew, 
 
 King's College, London. 
 Macpherson, W., Esq. 
 Maurice, Rev,, Professor. 
 Miller, W. H., Esq., M.Ao F.R.S. 
 MosELEY, Rev.H.,M.A., F.R.S. 
 MotJNTAJN, Rev. J. II. B., D.D. 
 Narrien, j., Esq^ F.R.A.S. 
 Ne^vman, Rev. J. H., B.D. 
 Nicholson, Peter, Esq. 
 Ormerod, T. Qm M,A.> Archdeacon of 
 Suffolk. 
 
 Ottley, Rev. J. B., M.A, 
 
 Peacock, Rev. G., D.D., Dean of Ely. 
 
 Phillips, John, Esq., Secrotaxy to ilie 
 British Association. 
 
 Procter, Capt,, Sandhurst. 
 
 Redding, Cyrus, Esq. 
 
 Renouahd, Rev. G, C, B.D,, F.R.S. 
 
 Richardson, Charles, Esq., LL.D. 
 
 Riddle, Rev. J. Eo M.A., Oxford. 
 
 RoGET, P. M., Esq., M.D., FJI.S. 
 
 RosCOE, Thomas, Esq. 
 
 Rose, Rev. Henry John, B.D. 
 
 Russell, Right Rev. Bishop. 
 
 Senioh, Nassau William, Esq. 
 
 Smedley, Rev. E., M.A. 
 
 SsiiTTT, G. H., Esq., F.Q.S. 
 
 South, J. F., Esq., F.L.S. 
 
 Sfookeb, W. C, Esq, 
 
 SrEPirENSj'j. Fo Esq„ F.L.S., F.Z.S. 
 
 Stoddakt, Sir J^ LLJ). 
 
 Talfoubd, Mr. Justice, 
 
 Taylor, W. C, Esq., LL.D. 
 
 Thompson, Rev.H., M.A., Senior Fellow 
 of St. John's, Cambridge. 
 
 ViGNOLES, C Esq., Civil Engineer. 
 
 WF.ST5IACOTT, R., Esq., F.R,S„ A.R,A. 
 
 WuATELY, Ric}iard« D.D., Archbishop 
 of Dublui. 
 
 Whewell, Rev,W.,D.D.,F.R.S., Master 
 of Trinity College, Cambridge, 
 
 Wix^uAUS, Robert, Esq., MJ>: 
 
 
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 1 
 
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 1^1 
 
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 ■^<; 
 
PLAN OF THE ENCYCL< 
 
 U.C.BERKELEY LIBRARIES 
 
 f; The INTRODITCTION.— On 
 'jj in the Language of 
 
 % .iTirst Dibifiion. 
 
 n 
 
 
 1:1 
 
 II 
 
 PURE SCIENCES. 
 
 Section- I. 
 Formal Sciencks. 
 Philosophy of Language. 
 Loiric. 
 Kliotoric. 
 Mathematics :— 
 Geometry. 
 Arithmetic. 
 Algebra. 
 
 Geometrical Analj'sis. 
 Theory of Numbers. 
 Trigonometry. 
 Analytical Geometry. 
 Conic yection.s. 
 Differential and Integral 
 
 Calculus. 
 Calouius of Variations. 
 Calculus of Finite Dif- 
 ferences. 
 Calculus of Functions. 
 Theory of Probabilities. 
 Definite Integrals. 
 Section II. 
 Real Sex EX(TK3. 
 Moral and Metaphj-sical 
 
 Philosophy. 
 Law :— 
 General Principles of Law, 
 Roman Law. 
 Engli.sh Law — 
 Laws of England. 
 Laws of Ireland. 
 Laws of Scotland. 
 Colonial Law. 
 Canon Law. 
 Politics : — 
 Law of Nations- 
 Diplomacy. 
 Political Philo-sophy— 
 
 Statistics. 
 Political Economy- 
 Commerce. 
 Theology :— 
 Natural Theology*. 
 Evidences of Ervelation. 
 Bcrintirre Doctrine. 
 Hiblical Literature, 
 IJihlical Antiiniitics. 
 Religions and lleligioiis 
 Cuiitoms. 
 
 Scronti Dill 16 ion. 
 
 MIXED AND APPLIED 
 SCIENCES. 
 
 iSkctfov I. 
 Mecttamcai, Pirn.nsoriiT. 
 C Mi id Mil t/tciiuUics. ) 
 Meclianics. 
 Hydrostatics. 
 Pneum.atics, 
 Optics. 
 
 Astronomy ^— 
 Plane Astronomy. 
 Nautical A.stronomy. 
 Physical Astronomy. 
 FiL'iirf of tlif Ivirrli. 
 
 the Laws an 
 tlio Schools, 
 
 Sep 
 
 EXPE) 
 
 Piirij 
 
 Macrnetiij 
 
 Elect ro-J 
 
 Electricity. 
 
 Galvanism. 
 
 Heat. 
 
 Light. 
 
 Chemistry. 
 
 Sound. 
 
 Meteorology. 
 
 Section III. 
 The Fine Ahts. 
 Arcliitecture. 
 Sculpture, 
 Painting. 
 Ileraldry. 
 Numismatics. 
 Poetrj'. 
 Music. 
 Engraving. 
 
 Section IV. 
 The Useful Akt8. 
 Agriculture. 
 Horticulture. 
 Floriculture. 
 Arboriculture. 
 Carpentry and Joinery 
 tortilication. 
 Engineering, 
 Naval Architechire. 
 Manufactures, 
 Mechanical Arts. 
 Chemical Arts. 
 
 Section V. 
 Natural IIistort. 
 Inanimate : — 
 Crystallography. 
 Mineralogy. 
 Geology. 
 Insentient .'— 
 
 Rotany, 
 Animate:— 
 ZoolocT. 
 PhysiolocT, 
 ComparatTre Auatonay 
 Vertebrals : 
 Mammalia. 
 Rinls, 
 Retitiles. 
 Fisiies. 
 In vertebrals: 
 Mdlluscj*. 
 
 fnst'cts. 
 'rustuceans. 
 Araohnid.'uis. 
 Myrianods. 
 Spincd .'skins. 
 Sea Nettles. 
 Infusorie* 
 Polyps. 
 
 Section VI. 
 
 AlTLK'ATIONS OP 
 NaTI ICAL HlSTOUV. 
 
 Anatomr, 
 Materia Me<lica: 
 
 Pharmacy. 
 Mi-dicine. 
 
 MiMU OIUUKAPHT. 
 
 Introduction : — 
 Dissertation ontlic Uses of 
 
 Ilistor)'. 
 Chronologv'. 
 Clironologi'cal Tables. 
 
 Arcileologt. 
 Ethnology. 
 Ancient IIistort :— . 
 
 Sacred History. 
 
 The Jews. 
 
 Greece. 
 
 Greek Literature. 
 
 Greek I'hilosophv and Art. 
 
 Ancient Oriental Nations. 
 
 Rome. 
 
 Roman Literature. 
 
 Roman Philosophy. 
 
 Classii-ftl Antiquitleau 
 
 Heathen Mythology. 
 
 Middle Ages. 
 Modern History :— 
 
 Tlie Christian Church. 
 
 Greek Empire. 
 
 Ottoman Empire. 
 
 The Crusades. 
 
 Italy. 
 
 Germany. 
 
 France. 
 
 Spain. 
 
 Portugal. 
 
 Netherlands- 
 Switzerland* 
 
 Britain. 
 
 America. 
 
 India. 
 
 iTourtJD Bibision. 
 
 GEOGRAPHY. 
 PnrsiCAL GEOGRArnT. 
 
 PoLmCAL GEOGBArilT :- 
 
 European. 
 
 American. 
 
 Orient;il. 
 
 African. 
 
 Chtssicjil. 
 BuiTisu ToroG2<\riiT. 
 
 jFift5 Dibisioii. 
 
 LEXICOGRAPHICAL. 
 
 Englisli lATcicon, .<s:c. &c &>■. 
 See Prospectus, 4 43. 
 
 GENERAL INDEX. 
 
 WW: 
 
 (J 
 
 
 
 l'^ 
 
 MM...-. 
 

 P 
 
 i